Description of Business and Basis of Presentation - Restatement Table - Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)		$ 165,735		$ 112,266	[1]	$ 103,991		$ 307,943	[1]
Depreciation and amortization		60,160	[2]	46,379	[1]	183,715	[2],[3]	132,236	[1]
Impairments		2,337	[2]	898	[1]	276,229	[2],[3]	2,431	[1]
Deferred income taxes						2,496		4,024	[1]
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net						15,816		34,965	[1]
As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)		162,752		$ 105,784	[4]	361,264		$ 293,705	[4]
Depreciation and amortization	[2]	63,351				190,114	[3]
Impairments	[2]	2,337				11,827	[3]
Deferred income taxes						2,993
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net						16,049
Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)		2,983				(257,273)
Depreciation and amortization	[2]	(3,191)				(6,399)	[3]
Impairments	[2]	$ 0				264,402	[3]
Deferred income taxes						(497)
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net						$ (233)

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

[2] “As Reported” amounts previously included as a component of Depreciation, amortization and impairments in WGP’s Original Filing.

[3] “As Reported” amounts previously included as a component of Depreciation, amortization and impairments in WGP’s Original Filing.

[4] See Adjustments to Previously Issued Financial Statements in Note 1.