19. Business Segments The Company identifies its segments using the "management approach," which designates the internal organization that is used by management for making operating decisions and assessing performance as the source of the Company's reportable segments. Management organizes the business based on geography, and has designated the regions Americas, EMEA, and APAC as reportable segments. The accounting policies of the Company's reportable segments are the same as those described in the summary of accounting policies in Note 2, "Summary of Significant Accounting Policies and Basis of Presentation." The Company evaluates segment performance based on an "Adjusted Operating EBITDA" basis. Adjusted Operating EBITDA (a non-GAAP measure) is defined as net earnings before interest, income taxes, other expense  net, depreciation and amortization expense plus certain other items such as gain or loss from impairment of disposal of assets, restructuring expense, separation expense, loss on modification or extinguishment of debt, acquisition-related transaction and integration costs and certain other items. In addition, certain corporate-level expenses and eliminations are not allocated to the segments. These unallocated expenses include corporate overhead, stock-based compensation expense and certain other non-operating expenses. The Company's presentation of Adjusted Operating EBITDA may not be comparable to similar measures used by other companies. Financial information relating to the Company's reportable segments for the three months ended March 31, 2019 and 2018 , respectively, is as follows: Three Months Ended March 31, (in millions, except percentage data) 2019 2018 Net sales: Americas $ 275.1 $ 280.2 EMEA 106.7 81.0 APAC 54.8 43.5 Elimination of intersegment sales (61.3 ) (54.3 ) Total net sales $ 375.3 $ 350.4 Segment Adjusted Operating EBITDA: Americas $ 40.8 $ 47.6 EMEA 18.3 14.1 APAC 7.9 5.5 Total Segment Adjusted Operating EBITDA 67.0 67.2 Corporate and unallocated (16.9 ) (11.9 ) Amortization expense (9.5 ) (7.9 ) Depreciation expense (4.9 ) (4.2 ) Transaction costs (1) (0.4 ) (1.2 ) Other items (2) (6.6 )  Separation expense (3)  (0.1 ) Restructuring expense (4.2 ) (0.4 ) Gain from disposal of assets  net  0.1 Earnings from operations 24.5 41.6 Interest expense (24.0 ) (20.3 ) Other expense  net (3.0 ) (8.5 ) (Loss) earnings before income taxes $ (2.5 ) $ 12.8 (1) Transaction costs are associated with acquisition and integrated-related activity. These costs include $0.2 million related to inventory fair value purchase accounting adjustments recorded in "Cost of sales" for the three months ended March 31, 2019 and $0.2 million and $1.2 million of professional services and other direct acquisition and integration costs recorded in "Selling, general and administrative expenses" for the three months ended March 31, 2019 and 2018, respectively. (2) Other items are costs, which are not representative of the Company's operational performance. For the three months ended March 31, 2019, these costs include $5.8 million of consultant costs for the Transformation Program and other professional fees of $0.8 million. Each of these costs have been recorded in "Selling, general and administrative expenses" for the three months ended March 31, 2019. (3) Separation expense is included within "Selling, general and administrative expenses" for the three months ended March 31, 2018. Adjusted Operating EBITDA % by segment (4) : Americas 14.8 % 17.0 % EMEA 17.2 % 17.4 % APAC 14.4 % 12.6 % (4) Adjusted Operating EBITDA % in the section above is calculated by dividing Adjusted Operating EBITDA by net sales for each respective segment. Net sales by geographic area (5) : United States $ 225.0 $ 223.4 Other Americas 20.3 28.5 EMEA 88.6 62.1 APAC 41.4 36.4 Total net sales by geographic area $ 375.3 $ 350.4 (5) Net sales in the section above are attributed to geographic regions based on location of customer. Net sales by product class and segment for the three months ended March 31, 2019 and 2018 are as follows: Three Months Ended March 31, 2019 (in millions) Commercial Foodservice Whole Goods Aftermarket Parts and Support Total Americas $ 202.6 $ 38.2 $ 240.8 EMEA 77.5 13.4 90.9 APAC 36.0 7.6 43.6 Total net sales $ 316.1 $ 59.2 $ 375.3 Three Months Ended March 31, 2018 (in millions) Commercial Foodservice Whole Goods Aftermarket Parts and Support Total Americas $ 209.1 $ 40.9 $ 250.0 EMEA 51.7 12.4 64.1 APAC 29.2 7.1 36.3 Total net sales $ 290.0 $ 60.4 $ 350.4 As of March 31, 2019 and December 31, 2018 , total assets by reportable segment are as follows: (in millions) March 31, 2019 December 31, 2018 Total assets by segment: Americas $ 1,572.4 $ 1,437.3 EMEA 380.3 324.2 APAC 186.3 169.0 Corporate 53.3 144.5 Total assets $ 2,192.3 $ 2,075.0