Commitments and Contingencies Litigation In the normal course of business, we are subject to various legal and regulatory proceedings. For such matters, we record liabilities when they are considered probable and estimable, based on currently available facts, our historical experience, and our estimates of the ultimate outcome or resolution of the liability in the future. While the outcome of these proceedings is uncertain and a loss in excess of the amount we have accrued is possible though not reasonably estimable, it is the opinion of management that any amounts exceeding the accruals will not have a material adverse impact on our financial position, results of operations or cash flows. We maintain liability insurance for various risks associated with the operation of our natural gas pipelines and facilities, including for property damage and bodily injury. These liability insurance policies generally require us to be responsible for the first $1.0 million (self-insured retention) of each incident. The National Transportation Safety Board (NTSB) is investigating an incident that occurred at a Dallas, Texas residence on February 23, 2018 that resulted in one fatality and injuries to four other residents. Together with the Railroad Commission of Texas and the Pipeline and Hazardous Materials Safety Administration, Atmos Energy is a party to the investigation and in that capacity is working closely with the NTSB to help determine the cause of this incident. On March 29, 2018 , a civil action was filed in Dallas, Texas against Atmos Energy in response to the February 23rd incident. The plaintiffs seek over $1.0 million in damages for, among with others, wrongful death and personal injury. We are a party to various other litigation or claims that have arisen in the ordinary course of our business. While the results of such litigation or claims cannot be predicted with certainty, we continue to believe the final outcome of such litigation or claims will not have a material adverse effect on our financial condition, results of operations or cash flows. Environmental Matters We are a party to environmental matters and claims that have arisen in the ordinary course of our business. While the ultimate results of response actions to these environmental matters and claims cannot be predicted with certainty, we believe the final outcome of such response actions will not have a material adverse effect on our financial condition, results of operations or cash flows because we believe that the expenditures related to such response actions will either be recovered through rates, shared with other parties or are adequately covered by insurance. Purchase Commitments Our distribution and pipeline and storage segments maintain supply contracts with several vendors that generally cover a period of up to one year. Commitments for estimated base gas volumes are established under these contracts on a monthly basis at contractually negotiated prices. Commitments for incremental daily purchases are made as necessary during the month in accordance with the terms of the individual contract. Our Mid-Tex Division maintains a limited number of long-term supply contracts to ensure a reliable source of gas for our customers in its service area which obligate it to purchase specified volumes at prices indexed to natural gas trading hubs. At September 30, 2018 , we were committed to purchase 54.1 Bcf within one year and 37.2 Bcf within two to three years under indexed contracts. Purchases under these contracts totaled $57.2 million , $49.7 million and $85.3 million for 2018 , 2017 and 2016 . Regulatory Matters The SEC and the Commodities Futures Trading Commission, pursuant to the DoddFrank Act, established numerous regulations relating to U.S. financial markets. We enacted procedures and modified existing business practices and contractual arrangements to comply with such regulations. There are, however, some rulemaking proceedings that have not yet been finalized, including those relating to capital and margin rules for (noncleared) swaps. We do not expect these rules to directly impact our business practices or collateral requirements. However, depending on the substance of these final rules, in addition to certain international regulatory requirements still under development that are similar to DoddFrank, our swap counterparties could be subject to additional and potentially significant capitalization requirements. These regulations could motivate counterparties to increase our collateral requirements or cash postings. As of September 30, 2018 , formula rate mechanisms were pending regulatory approval in our Mississippi and Tennessee service areas, infrastructure mechanisms were pending regulatory approval in our Mississippi service area and rate cases were pending regulatory approval in our Kentucky, Mid-Tex, Virginia and West Texas service areas. These regulatory proceedings are discussed in further detail above in the Business  Ratemaking Activity section. Additionally, as discussed in further detail in Note 12, all jurisdictions are addressing impacts of the TCJA.