Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accrued capital expenditures	$ 173,981	$ 159,811
Accrued gathering, compression, processing, and transportation expenses	83,474	75,223
Accrued marketing expenses	30,123	52,822
Accrued interest expense	45,628	35,533
Other accrued liabilities	85,146	70,414
Total accrued liabilities	$ 418,352	$ 393,803