Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015		Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Interest expense	[1]	$ 31,301	$ 31,773	[2]	$ 76,869	$ 82,339	[2]
Third Parties [Member]
Debt Instrument [Line Items]
Long-term debt		31,795	26,972		88,123	75,047
Amortization of debt issuance costs and commitment fees		2,022	1,530		5,517	4,196
Capitalized interest		(1,343)	(1,039)		(4,674)	(6,826)
Interest expense		32,474	27,463		88,966	72,417
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[3]	(1,173)	4,310		(12,097)	9,922
Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Interest expense, affiliate	[4]	(1,173)	4,310		(12,097)	9,920
Affiliates [Member] | Working Capital Facility [Member]
Debt Instrument [Line Items]
Interest expense, affiliate		$ 0	$ 0		$ 0	$ 2

[1] Includes affiliate (as defined in Note 1) amounts of $1.2 million and $12.1 million for the three and nine months ended September 30, 2016, respectively, and $(4.3) million and $(9.9) million for the three and nine months ended September 30, 2015, respectively. See Note 2 and Note 9.

[2] Financial information has been recast to include the financial position and results attributable to the Springfield interest. See Note 1 and Note 2.

[3] For the three and nine months ended September 30, 2016, includes WES’s accretion revisions to the Deferred purchase price obligation - Anadarko (see Note 2 and Note 9) and for the nine months ended September 30, 2015, includes interest expense recognized on the WGP WCF (see Note 9).

[4] See Note 2 for a discussion of the accretion and net present value of the Deferred purchase price obligation - Anadarko.