Equity Investments	12 Months Ended
Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	Equity Investments We have a 20% ownership interest in Independence Hub, which owns the “Independence Hub” platform located in Mississippi Canyon Block 920 in a water depth of 8,000 feet. We previously had a 50% ownership interest in Deepwater Gateway, which owns and operates a tension leg platform production hub primarily for Anadarko Petroleum Corporation’s Marco Polo field in the Deepwater Gulf of Mexico. Our Production Facilities segment includes our investment in Independence Hub that is accounted for using the equity method of accounting, and previously included our former ownership interest in Deepwater Gateway. In December 2015, we were notified that the operator of the facility no longer forecasted utilization of the “Independence Hub” platform and planned to turn over the platform for decommissioning. As a result of this determination, Independence Hub recorded an impairment charge of $343.3 million to reduce the carrying amount of the platform assets to their estimated fair value of zero. For the year ended December 31, 2015, we recorded losses totaling $74.9 million to account for our 20% share of losses from Independence Hub and to write off the remaining capitalized interest of $3.6 million and a $1.0 million participation fee that we paid in 2004. For the years ended December 31, 2017 and 2016, we recorded losses totaling $2.4 million and $2.2 million, respectively, to account for our share of losses from Independence Hub. Since we are committed to providing the necessary level of financial support to enable Independence Hub to pay its obligations as they become due, we recorded liabilities of $9.8 million and $10.2 million at December 31, 2017 and 2016, respectively, for our share of the estimated obligations, net of remaining working capital. These liabilities are reflected in “Accrued liabilities” and “Other non-current liabilities” in the accompanying consolidated balance sheets. We did not receive any cash distributions from Independence Hub in 2016 or 2017. For the year ended December 31, 2015, we received a cash distribution of $1.8 million. Additionally in December 2015, Deepwater Gateway recorded an impairment charge of $96.7 million to reduce the carrying amount of its long-lived assets to their estimated fair value of $70.8 million. For the year ended December 31, 2015, we recorded losses totaling $49.4 million to account for our 50% share of losses from Deepwater Gateway and to write off the remaining capitalized interest of $1.2 million. These losses included our share of an impairment charge that Deepwater Gateway recorded in December 2015. For the year ended December 31, 2015, we received a cash distribution of $5.2 million from Deepwater Gateway. In February 2016, we received a cash distribution of $1.2 million and sold our ownership interest in Deepwater Gateway to a subsidiary of Genesis for $25 million. Equity method investments were immaterial to our 2016 and 2017 consolidated financial results. For the year ended December 31, 2015, the summarized aggregated revenues, operating loss and net loss related to our equity method investments were $14.8 million, $448.1 million and $448.1 million, respectively.

Equity Investments

We have a 20% ownership interest in Independence Hub, which owns the “Independence Hub” platform located in Mississippi Canyon Block 920 in a water depth of 8,000 feet. We previously had a 50% ownership interest in Deepwater Gateway, which owns and operates a tension leg platform production hub primarily for Anadarko Petroleum Corporation’s Marco Polo field in the Deepwater Gulf of Mexico. Our Production Facilities segment includes our investment in Independence Hub that is accounted for using the equity method of accounting, and previously included our former ownership interest in Deepwater Gateway.

In December 2015, we were notified that the operator of the facility no longer forecasted utilization of the “Independence Hub” platform and planned to turn over the platform for decommissioning. As a result of this determination, Independence Hub recorded an impairment charge of $343.3 million to reduce the carrying amount of the platform assets to their estimated fair value of zero. For the year ended December 31, 2015, we recorded losses totaling $74.9 million to account for our 20% share of losses from Independence Hub and to write off the remaining capitalized interest of $3.6 million and a $1.0 million participation fee that we paid in 2004. For the years ended December 31, 2017 and 2016, we recorded losses totaling $2.4 million and $2.2 million, respectively, to account for our share of losses from Independence Hub. Since we are committed to providing the necessary level of financial support to enable Independence Hub to pay its obligations as they become due, we recorded liabilities of $9.8 million and $10.2 million at December 31, 2017 and 2016, respectively, for our share of the estimated obligations, net of remaining working capital. These liabilities are reflected in “Accrued liabilities” and “Other non-current liabilities” in the accompanying consolidated balance sheets. We did not receive any cash distributions from Independence Hub in 2016 or 2017. For the year ended December 31, 2015, we received a cash distribution of $1.8 million.

Additionally in December 2015, Deepwater Gateway recorded an impairment charge of $96.7 million to reduce the carrying amount of its long-lived assets to their estimated fair value of $70.8 million. For the year ended December 31, 2015, we recorded losses totaling $49.4 million to account for our 50% share of losses from Deepwater Gateway and to write off the remaining capitalized interest of $1.2 million. These losses included our share of an impairment charge that Deepwater Gateway recorded in December 2015. For the year ended December 31, 2015, we received a cash distribution of $5.2 million from Deepwater Gateway. In February 2016, we received a cash distribution of $1.2 million and sold our ownership interest in Deepwater Gateway to a subsidiary of Genesis for $25 million.

Equity method investments were immaterial to our 2016 and 2017 consolidated financial results. For the year ended December 31, 2015, the summarized aggregated revenues, operating loss and net loss related to our equity method investments were $14.8 million, $448.1 million and $448.1 million, respectively.