some of the significant challenges we face are as follows : dependence upon u.s. government programs and contracts , future reductions or changes in u.s. government spending in our markets , successful implementation of our cost reduction plans , environmental matters , capital structure , underfunded retirement benefit plans , and information technology and cyber security . major customers the principal end user customers of our products and technology are primarily agencies of the u.s. government . since a majority of our sales are , directly or indirectly , to the u.s. government , funding for the purchase of our products and services generally follows trends in u.s. aerospace and defense spending . however , individual u.s. government agencies , which include the military services , nasa , the missile defense agency , and the prime contractors that serve these agencies , exercise independent purchasing power within `` budget top-line `` limits . therefore , sales to the u.s. government are not regarded as sales to one customer , but rather each contracting agency is viewed as a separate customer . 18 the following table summarizes net sales to the u.s. government and its agencies , including net sales to significant customers disclosed below : replace_table_token_5_th the following table summarizes net sales by principal end user in 2018 : replace_table_token_6_th the following table summarizes the percentages of net sales for significant programs , all of which are included in the u.s. government sales and are comprised of multiple contracts : replace_table_token_7_th the following table summarizes customers that represented more than 10 % of net sales , each of which involves sales of several product lines and programs : replace_table_token_8_th industry update information concerning our industry appears in part i , item 1. business under the caption `` industry overview . `` competitive improvement program during 2015 , we initiated phase i of our cip comprised of activities and initiatives aimed at reducing costs in order for us to continue to compete successfully . phase i is comprised of three major components : ( i ) facilities optimization and footprint reduction ; ( ii ) product affordability ; and ( iii ) reduced administrative and overhead costs . on april 6 , 2017 , the board of directors approved phase ii of our previously announced cip . pursuant to phase ii , we expanded cip and further consolidated our sacramento , california , and gainesville , virginia sites , while centralizing and expanding our existing presence in huntsville , alabama . when fully implemented , we anticipate that the cip will result in annual costs that are $ 230 million below levels anticipated prior to cip . we currently estimate that we will incur restructuring and related costs of the phase i and ii programs of approximately $ 210.0 million ( including approximately $ 60.5 million of capital expenditures ) . our current estimate is down from the initial estimate of $ 235.0 million primarily due to efficiencies in program transitions and lower than expected employee costs . we have incurred $ 131.4 million of such costs through december 31 , 2018 , including $ 48.1 million in capital expenditures . 19 environmental matters our current and former business operations are subject to , and affected by , federal , state , local , and foreign environmental laws and regulations relating to the discharge , treatment , storage , disposal , investigation , and remediation of certain materials , substances , and wastes . see notes 8 ( c ) and 8 ( d ) in the consolidated financial statements in item 8 of this report and `` environmental matters `` below for summary of our environmental reserve activity . capital structure we have a substantial amount of debt for which we are required to make interest and principal payments . interest on long-term financing is not a recoverable cost under our u.s. government contracts . as of december 31 , 2018 , we had $ 625.4 million of debt outstanding . in 2018 , we entered into an industrial bond transaction with a subsidiary to realize property tax savings . retirement benefits as of the last measurement date at december 31 , 2018 , the pension assets , projected benefit obligations , and unfunded pension obligation were $ 894.8 million , $ 1,288.7 million , and $ 393.9 million , respectively . we estimate that 82 % of our unfunded pension obligation as of december 31 , 2018 , is related to our u.s. government contracting business , aerojet rocketdyne . on september 10 , 2018 , we made a discretionary contribution of 2.7 million treasury stock , or $ 95.0 million , of our common stock to our tax-qualified defined benefit pension plan . this voluntary contribution will help address the current underfunding of the tax-qualified defined benefit pension plan . this contribution was tax deductible in the current period and will be used as a pre-funding credit . we expect to make cash contributions of approximately $ 37.0 million to our tax-qualified defined benefit pension plan in 2019. we generally are able to recover cash contributions related to our tax-qualified defined benefit pension plan as allowable costs on our u.s. government contracts , but there can be differences between when we contribute cash to our tax-qualified defined benefit pension plan under pension funding rules and recover it under cas . information technology and cyber security we routinely experience cyber security threats , threats to our information technology infrastructure and unauthorized attempts to gain access to our sensitive information , as do our customers , suppliers , subcontractors , and other partners . in 2017 , we outsourced certain information technology and cyber security functions to third-party contractors in order to take advantage of advanced cyber security technologies . story_separator_special_tag further , as a result of the 2016 calendar , aerojet rocketdyne had 53 weeks of operations in 2016 compared with 52 weeks of operations in 2017. the additional week of operations , which occurred in the fourth quarter of 2016 and accounted for $ 32.2 million in additional net sales , is included in the above discussion of program changes . segment margin before environmental remediation provision adjustments , retirement benefits , net , and unusual items in 2017 compared with 2016 was up 30 basis points . items that had a significant impact were favorable contract performance on numerous programs as a result of overhead cost reductions and reduced program risks , most notably on the thaad program , partially offset by cost growth and manufacturing inefficiencies in 2017 on electric propulsion contracts . real estate segment replace_table_token_20_th in 2018 , we recognized net sales of $ 1.4 million from a land sale of 57 acres of the sacramento land . during 2017 and 2016 , net sales and segment performance consisted primarily of rental property operations . backlog : as of december 31 , 2018 , our total remaining performance obligations , also referred to as backlog , totaled $ 4.1 billion . we expect to recognize approximately 45 % , or $ 1.8 billion , of the remaining performance obligations as sales over the next twelve months , an additional 29 % the following twelve months , and 26 % thereafter . the following table summarizes backlog : replace_table_token_21_th our adoption of the new revenue recognition guidance accelerated the timing of revenue recognition on some of our contracts which resulted in a $ 0.6 billion reduction in our backlog as of december 31 , 2017. total backlog includes both funded backlog ( unfilled orders for which funding is authorized , appropriated and contractually obligated by the customer ) and unfunded backlog ( firm orders for which funding has not been appropriated ) . indefinite delivery and quantity contracts and unexercised options are not reported in total backlog . backlog is subject to funding delays or program restructurings/cancellations which are beyond our control . 25 use of non-gaap financial measures : in addition to segment performance ( discussed above ) , we provide the non-gaap financial measures of our performance called adjusted ebitdap , adjusted net income , and adjusted eps . we use these metrics to measure our operating and total company performance . we believe that for management and investors to effectively compare core performance from period to period , the metrics should exclude items that are not indicative of , or are unrelated to , results from our ongoing business operations such as retirement benefits ( pension and postretirement benefits ) , significant non-cash expenses , the impacts of financing decisions on earnings , and items incurred outside the ordinary , on-going and customary course of our business . accordingly , we define adjusted ebitdap as gaap net income ( loss ) adjusted to exclude interest expense , interest income , income taxes , depreciation and amortization , retirement benefits net of amounts that are recoverable under our u.s. government contracts , and unusual items which we do not believe are reflective of such ordinary , on-going and customary activities . adjusted net income and adjusted eps exclude retirement benefits net of amounts that are recoverable under our u.s. government contracts and unusual items which we do not believe are reflective of such ordinary , on-going and customary activities . adjusted net income and adjusted eps do not represent , and should not be considered an alternative to , net income ( loss ) or diluted eps as determined in accordance with gaap . replace_table_token_22_th _ ( 1 ) the income tax impact is calculated using the federal and state statutory rates in the corresponding year . we also provide the non-gaap financial measure of free cash flow . free cash flow , a non-gaap financial measure , is defined as cash flow from operating activities less capital expenditures . free cash flow should not be considered in isolation , as a measure of residual cash flow available for discretionary purposes , or as an alternative to cash flows from operations presented in accordance with gaap . we use free cash flow , both in presenting our results to stakeholders and the investment community , and in our internal evaluation and management of the business . management believes that this financial measure is useful because it provides supplemental information to assist investors in viewing the business using the same tools that management uses to evaluate progress in achieving our goals ( including under our annual cash and long-term compensation 26 incentive plans ) . the following table summarizes free cash flow : replace_table_token_23_th _ ( 1 ) free cash flow , a non-gaap financial measure , is defined as cash flow from operating activities less capital expenditures . because our method for calculating these non-gaap measures may differ from other companies ' methods , the non-gaap measures presented above may not be comparable to similarly titled measures reported by other companies . these measures are not recognized in accordance with gaap , and we do not intend for this information to be considered in isolation or as a substitute for gaap measures . environmental matters : our policy is to conduct our businesses with due regard for the preservation and protection of the environment . we devote a significant amount of resources and management attention to environmental matters and actively manage our ongoing processes to comply with environmental laws and regulations . we are involved in the remediation of environmental conditions that resulted from generally accepted manufacturing and disposal practices at certain plants in the 1950s and 1960s . in addition , we have been designated a prp with other companies at third party sites undergoing investigation and remediation . estimating environmental remediation costs is difficult due to the significant uncertainties inherent in these

debt activity the following table summarizes our debt principal activity : replace_table_token_29_th on september 20 , 2018 , we amended our senior credit facility to a $ 1.0 billion commitment ( see note 6 in the consolidated financial statements in item 8 of this report ) . outlook short-term liquidity requirements consist primarily of recurring operating expenses , including but not limited to costs related to our capital and environmental expenditures , company-funded r & d expenditures , debt service requirements , and retirement benefit plans . we believe that our existing cash and cash equivalents and availability under the senior credit facility coupled with cash generated from our future operations will provide sufficient funds to meet our operating plan for the next twelve months . the operating plan for this period provides for full operation of our businesses , including interest and debt payments . as of december 31 , 2018 , we had $ 735.3 million of cash and cash equivalents as well as $ 620.6 million of available borrowings under our senior credit facility . based on our existing debt agreements , we were in compliance with our financial and non-financial covenants as of december 31 , 2018 . our failure to comply with these covenants could result in an event of default that , if not cured or waived by the lenders , could result in the acceleration of the senior credit facility and 2¼ % notes . in addition , our failure to pay principal and interest when due is a default under the senior credit facility , and in certain cases , would cause a cross default on the 2¼ % notes . we are committed to a cash management strategy that maintains liquidity to adequately support the operation of the business , our growth strategy and to withstand unanticipated business volatility .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```debt activity the following table summarizes our debt principal activity : replace_table_token_29_th on september 20 , 2018 , we amended our senior credit facility to a $ 1.0 billion commitment ( see note 6 in the consolidated financial statements in item 8 of this report ) . outlook short-term liquidity requirements consist primarily of recurring operating expenses , including but not limited to costs related to our capital and environmental expenditures , company-funded r & d expenditures , debt service requirements , and retirement benefit plans . we believe that our existing cash and cash equivalents and availability under the senior credit facility coupled with cash generated from our future operations will provide sufficient funds to meet our operating plan for the next twelve months . the operating plan for this period provides for full operation of our businesses , including interest and debt payments . as of december 31 , 2018 , we had $ 735.3 million of cash and cash equivalents as well as $ 620.6 million of available borrowings under our senior credit facility . based on our existing debt agreements , we were in compliance with our financial and non-financial covenants as of december 31 , 2018 . our failure to comply with these covenants could result in an event of default that , if not cured or waived by the lenders , could result in the acceleration of the senior credit facility and 2¼ % notes . in addition , our failure to pay principal and interest when due is a default under the senior credit facility , and in certain cases , would cause a cross default on the 2¼ % notes . we are committed to a cash management strategy that maintains liquidity to adequately support the operation of the business , our growth strategy and to withstand unanticipated business volatility .
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 Suspicious Activity Report : some of the significant challenges we face are as follows : dependence upon u.s. government programs and contracts , future reductions or changes in u.s. government spending in our markets , successful implementation of our cost reduction plans , environmental matters , capital structure , underfunded retirement benefit plans , and information technology and cyber security . major customers the principal end user customers of our products and technology are primarily agencies of the u.s. government . since a majority of our sales are , directly or indirectly , to the u.s. government , funding for the purchase of our products and services generally follows trends in u.s. aerospace and defense spending . however , individual u.s. government agencies , which include the military services , nasa , the missile defense agency , and the prime contractors that serve these agencies , exercise independent purchasing power within `` budget top-line `` limits . therefore , sales to the u.s. government are not regarded as sales to one customer , but rather each contracting agency is viewed as a separate customer . 18 the following table summarizes net sales to the u.s. government and its agencies , including net sales to significant customers disclosed below : replace_table_token_5_th the following table summarizes net sales by principal end user in 2018 : replace_table_token_6_th the following table summarizes the percentages of net sales for significant programs , all of which are included in the u.s. government sales and are comprised of multiple contracts : replace_table_token_7_th the following table summarizes customers that represented more than 10 % of net sales , each of which involves sales of several product lines and programs : replace_table_token_8_th industry update information concerning our industry appears in part i , item 1. business under the caption `` industry overview . `` competitive improvement program during 2015 , we initiated phase i of our cip comprised of activities and initiatives aimed at reducing costs in order for us to continue to compete successfully . phase i is comprised of three major components : ( i ) facilities optimization and footprint reduction ; ( ii ) product affordability ; and ( iii ) reduced administrative and overhead costs . on april 6 , 2017 , the board of directors approved phase ii of our previously announced cip . pursuant to phase ii , we expanded cip and further consolidated our sacramento , california , and gainesville , virginia sites , while centralizing and expanding our existing presence in huntsville , alabama . when fully implemented , we anticipate that the cip will result in annual costs that are $ 230 million below levels anticipated prior to cip . we currently estimate that we will incur restructuring and related costs of the phase i and ii programs of approximately $ 210.0 million ( including approximately $ 60.5 million of capital expenditures ) . our current estimate is down from the initial estimate of $ 235.0 million primarily due to efficiencies in program transitions and lower than expected employee costs . we have incurred $ 131.4 million of such costs through december 31 , 2018 , including $ 48.1 million in capital expenditures . 19 environmental matters our current and former business operations are subject to , and affected by , federal , state , local , and foreign environmental laws and regulations relating to the discharge , treatment , storage , disposal , investigation , and remediation of certain materials , substances , and wastes . see notes 8 ( c ) and 8 ( d ) in the consolidated financial statements in item 8 of this report and `` environmental matters `` below for summary of our environmental reserve activity . capital structure we have a substantial amount of debt for which we are required to make interest and principal payments . interest on long-term financing is not a recoverable cost under our u.s. government contracts . as of december 31 , 2018 , we had $ 625.4 million of debt outstanding . in 2018 , we entered into an industrial bond transaction with a subsidiary to realize property tax savings . retirement benefits as of the last measurement date at december 31 , 2018 , the pension assets , projected benefit obligations , and unfunded pension obligation were $ 894.8 million , $ 1,288.7 million , and $ 393.9 million , respectively . we estimate that 82 % of our unfunded pension obligation as of december 31 , 2018 , is related to our u.s. government contracting business , aerojet rocketdyne . on september 10 , 2018 , we made a discretionary contribution of 2.7 million treasury stock , or $ 95.0 million , of our common stock to our tax-qualified defined benefit pension plan . this voluntary contribution will help address the current underfunding of the tax-qualified defined benefit pension plan . this contribution was tax deductible in the current period and will be used as a pre-funding credit . we expect to make cash contributions of approximately $ 37.0 million to our tax-qualified defined benefit pension plan in 2019. we generally are able to recover cash contributions related to our tax-qualified defined benefit pension plan as allowable costs on our u.s. government contracts , but there can be differences between when we contribute cash to our tax-qualified defined benefit pension plan under pension funding rules and recover it under cas . information technology and cyber security we routinely experience cyber security threats , threats to our information technology infrastructure and unauthorized attempts to gain access to our sensitive information , as do our customers , suppliers , subcontractors , and other partners . in 2017 , we outsourced certain information technology and cyber security functions to third-party contractors in order to take advantage of advanced cyber security technologies . story_separator_special_tag further , as a result of the 2016 calendar , aerojet rocketdyne had 53 weeks of operations in 2016 compared with 52 weeks of operations in 2017. the additional week of operations , which occurred in the fourth quarter of 2016 and accounted for $ 32.2 million in additional net sales , is included in the above discussion of program changes . segment margin before environmental remediation provision adjustments , retirement benefits , net , and unusual items in 2017 compared with 2016 was up 30 basis points . items that had a significant impact were favorable contract performance on numerous programs as a result of overhead cost reductions and reduced program risks , most notably on the thaad program , partially offset by cost growth and manufacturing inefficiencies in 2017 on electric propulsion contracts . real estate segment replace_table_token_20_th in 2018 , we recognized net sales of $ 1.4 million from a land sale of 57 acres of the sacramento land . during 2017 and 2016 , net sales and segment performance consisted primarily of rental property operations . backlog : as of december 31 , 2018 , our total remaining performance obligations , also referred to as backlog , totaled $ 4.1 billion . we expect to recognize approximately 45 % , or $ 1.8 billion , of the remaining performance obligations as sales over the next twelve months , an additional 29 % the following twelve months , and 26 % thereafter . the following table summarizes backlog : replace_table_token_21_th our adoption of the new revenue recognition guidance accelerated the timing of revenue recognition on some of our contracts which resulted in a $ 0.6 billion reduction in our backlog as of december 31 , 2017. total backlog includes both funded backlog ( unfilled orders for which funding is authorized , appropriated and contractually obligated by the customer ) and unfunded backlog ( firm orders for which funding has not been appropriated ) . indefinite delivery and quantity contracts and unexercised options are not reported in total backlog . backlog is subject to funding delays or program restructurings/cancellations which are beyond our control . 25 use of non-gaap financial measures : in addition to segment performance ( discussed above ) , we provide the non-gaap financial measures of our performance called adjusted ebitdap , adjusted net income , and adjusted eps . we use these metrics to measure our operating and total company performance . we believe that for management and investors to effectively compare core performance from period to period , the metrics should exclude items that are not indicative of , or are unrelated to , results from our ongoing business operations such as retirement benefits ( pension and postretirement benefits ) , significant non-cash expenses , the impacts of financing decisions on earnings , and items incurred outside the ordinary , on-going and customary course of our business . accordingly , we define adjusted ebitdap as gaap net income ( loss ) adjusted to exclude interest expense , interest income , income taxes , depreciation and amortization , retirement benefits net of amounts that are recoverable under our u.s. government contracts , and unusual items which we do not believe are reflective of such ordinary , on-going and customary activities . adjusted net income and adjusted eps exclude retirement benefits net of amounts that are recoverable under our u.s. government contracts and unusual items which we do not believe are reflective of such ordinary , on-going and customary activities . adjusted net income and adjusted eps do not represent , and should not be considered an alternative to , net income ( loss ) or diluted eps as determined in accordance with gaap . replace_table_token_22_th _ ( 1 ) the income tax impact is calculated using the federal and state statutory rates in the corresponding year . we also provide the non-gaap financial measure of free cash flow . free cash flow , a non-gaap financial measure , is defined as cash flow from operating activities less capital expenditures . free cash flow should not be considered in isolation , as a measure of residual cash flow available for discretionary purposes , or as an alternative to cash flows from operations presented in accordance with gaap . we use free cash flow , both in presenting our results to stakeholders and the investment community , and in our internal evaluation and management of the business . management believes that this financial measure is useful because it provides supplemental information to assist investors in viewing the business using the same tools that management uses to evaluate progress in achieving our goals ( including under our annual cash and long-term compensation 26 incentive plans ) . the following table summarizes free cash flow : replace_table_token_23_th _ ( 1 ) free cash flow , a non-gaap financial measure , is defined as cash flow from operating activities less capital expenditures . because our method for calculating these non-gaap measures may differ from other companies ' methods , the non-gaap measures presented above may not be comparable to similarly titled measures reported by other companies . these measures are not recognized in accordance with gaap , and we do not intend for this information to be considered in isolation or as a substitute for gaap measures . environmental matters : our policy is to conduct our businesses with due regard for the preservation and protection of the environment . we devote a significant amount of resources and management attention to environmental matters and actively manage our ongoing processes to comply with environmental laws and regulations . we are involved in the remediation of environmental conditions that resulted from generally accepted manufacturing and disposal practices at certain plants in the 1950s and 1960s . in addition , we have been designated a prp with other companies at third party sites undergoing investigation and remediation . estimating environmental remediation costs is difficult due to the significant uncertainties inherent in these

