Accrued Liabilities (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accrued Liabilities, Current [Abstract]
Interest payable	$ 17,247	$ 6,321
Lease operating expenses	12,751	17,220
Taxes	10,717	3,767
Employee costs	11,718	12,641
Third-party credits	2,831	3,326
Derivative settlements	26	0
Other	2,429	3,643
Total accrued liabilities	$ 57,719	$ 46,918