Decommissioning and Other Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Decommissioning and Other Asset Retirement Obligations Detail [Table]
Beginning balance for the period, as reported	$ 62,741	$ 50,904
Activity in the period:
Accretion of liability	2,000	728
Retirement obligations incurred	0	39,187
Revisions in estimated cash flows		35,241
Settlement of retirement obligations	(10,633)	(63,319)
Ending balance at December 31	57,449	62,741	$ 50,904
Change in estimated cash flows to decommission oil and gas properties	3,341
Direct charges to operating expense for increased estimated cash flows	2,661	72,724	$ 75,312
Estimated future hurricane repair expenses	7,800
Asset retirement obligations associated with non-operated properties	$ 9,100	$ 8,400