Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Interest expense	[1]	$ (40,346)	$ (36,033)
Third Parties [Member]
Debt Instrument [Line Items]
Long-term and short-term debt		(41,536)	(34,814)
Amortization of debt issuance costs and commitment fees		(2,864)	(1,964)
Capitalized interest		4,054	816
Interest expense		(40,346)	(35,962)
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[2]	0	(71)
Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Interest expense, affiliate	[3]	$ 0	$ (71)

[1] Includes affiliate (as defined in Note 1) amounts of zero and $(0.1) million for the three months ended March 31, 2018 and 2017, respectively. See Note 10.

[2] Includes amounts related to the Deferred purchase price obligation - Anadarko (see Note 3 and Note 10).

[3] See Note 3 for a discussion of the Deferred purchase price obligation - Anadarko.