Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued capital expenditures	$ 159,811	$ 271,542
Accrued gathering, compression, processing, and transportation expenses	75,223	59,962
Accrued marketing expenses	52,822	38,136
Accrued interest expense	35,533	26,391
Other accrued liabilities	70,414	92,294
Total accrued liabilities	$ 393,803	$ 488,325