Property, Plant and Equipment	9 Months Ended
Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	5. Property, Plant and Equipment Diamond Offshore Asset Impairments During the third quarter of 2017, Diamond Offshore evaluated six drilling rigs with indicators of impairment. Based on its assumptions and analyses, Diamond Offshore determined that the carrying values of these rigs were not impaired. If market fundamentals in the offshore oil and gas industry deteriorate further or a market recovery is delayed, additional impairment losses may be required to be recognized in future periods. During the second quarter of 2017, Diamond Offshore evaluated seven drilling rigs with indicators of impairment. Due to the continued deterioration of market fundamentals in the contract drilling industry, as well as newly-available market projections, which indicated that a full market recovery is likely to occur further in the future than had previously been estimated, Diamond Offshore determined that the carrying values of one ultra-deepwater and one deepwater semisubmersible rig were impaired. Diamond Offshore estimated the fair value of the rigs impaired in 2017 using an income approach, whereby the fair value of each rig was estimated based on a calculation of the rig’s future net cash flows. These calculations utilized significant unobservable inputs, including estimated proceeds that may be received on ultimate disposition of the rig, and are representative of Level 3 fair value measurements due to the significant level of estimation involved and lack of transparency as to the inputs used. During the second quarter of 2017, Diamond Offshore recorded an asset impairment charge of $72 million ($23 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income. Diamond Offshore recorded aggregate asset impairment charges of $672 million ($263 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income for the nine months ended September 30, 2016. See Note 6 of the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 for further discussion of Diamond Offshore’s 2016 asset impairments. Boardwalk Pipeline Sale of Assets In May of 2017, Boardwalk Pipeline sold a processing plant and related assets, for approximately $64 million, including customary adjustments. The sale resulted in a loss of $47 million ($15 million after tax and noncontrolling interests) and is included in Other operating expenses on the Consolidated Condensed Statements of Income.

5. Property, Plant and Equipment

Diamond Offshore

Asset Impairments

During the third quarter of 2017, Diamond Offshore evaluated six drilling rigs with indicators of impairment. Based on its assumptions and analyses, Diamond Offshore determined that the carrying values of these rigs were not impaired. If market fundamentals in the offshore oil and gas industry deteriorate further or a market recovery is delayed, additional impairment losses may be required to be recognized in future periods.

During the second quarter of 2017, Diamond Offshore evaluated seven drilling rigs with indicators of impairment. Due to the continued deterioration of market fundamentals in the contract drilling industry, as well as newly-available market projections, which indicated that a full market recovery is likely to occur further in the future than had previously been estimated, Diamond Offshore determined that the carrying values of one ultra-deepwater and one deepwater semisubmersible rig were impaired.

Diamond Offshore estimated the fair value of the rigs impaired in 2017 using an income approach, whereby the fair value of each rig was estimated based on a calculation of the rig’s future net cash flows. These calculations utilized significant unobservable inputs, including estimated proceeds that may be received on ultimate disposition of the rig, and are representative of Level 3 fair value measurements due to the significant level of estimation involved and lack of transparency as to the inputs used. During the second quarter of 2017, Diamond Offshore recorded an asset impairment charge of $72 million ($23 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income.

Diamond Offshore recorded aggregate asset impairment charges of $672 million ($263 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income for the nine months ended September 30, 2016. See Note 6 of the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 for further discussion of Diamond Offshore’s 2016 asset impairments.

Boardwalk Pipeline

Sale of Assets

In May of 2017, Boardwalk Pipeline sold a processing plant and related assets, for approximately $64 million, including customary adjustments. The sale resulted in a loss of $47 million ($15 million after tax and noncontrolling interests) and is included in Other operating expenses on the Consolidated Condensed Statements of Income.