Additional Balance Sheet Details (Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued interest	$ 30,099	$ 48,908
Accounts payable	27,875	30,477
Accrued lease operating expenses	26,656	37,549
Accrued compensation	25,813	46,780
Taxes payable	25,386	32,438
Accrued exploration and development costs	6,309	20,892
Other	31,632	36,153
Total	$ 173,770	$ 253,197