Additional Balance Sheet Details (Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued interest	$ 29,182	$ 48,908
Accrued lease operating expenses	28,482	37,549
Accounts payable	24,675	30,477
Taxes payable	19,342	32,438
Accrued compensation	16,423	46,780
Accrued exploration and development costs	4,906	20,892
Other	39,324	36,153
Total	$ 162,334	$ 253,197