Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Interest expense		$ (48,316)	$ (36,117)	$ (133,359)	$ (108,447)
Third Parties [Member]
Debt Instrument [Line Items]
Long-term and short-term debt		(53,229)	(36,223)	(143,436)	(106,412)
Amortization of debt issuance costs and commitment fees		(2,054)	(2,009)	(6,955)	(5,955)
Capitalized interest		6,967	2,115	17,032	3,991
Interest expense		(48,316)	(36,117)	(133,359)	(108,376)
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[1]	0	0	0	(71)
Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Deferred purchase price obligation - Anadarko	[2]	$ 0	$ 0	$ 0	$ (71)

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

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