Sale of Equity Method Investment (Notes)

12 Months Ended

Dec. 31, 2017

Subsidiary, Sale of Stock [Line Items]

Equity Method Investments and Joint Ventures Disclosure [Text Block]

 Sale of Equity Method Investment

On October 2, 2017, we sold our 50% interest in OKCO2, a joint venture that owns a carbon dioxide liquefaction and purification facility, to the joint venture partner. Prior to the sale, we had accounted for this interest as an equity method investment. We received proceeds of $16.3 million for the sale and recorded a gain of $14.3 million after the completion of certain customary closing and working capital adjustments in the fourth quarter of 2017. The proceeds were included in the determination of Available Cash for the fourth quarter of 2017.