Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net (Loss) Income Attributable to Parent	$ (3,207,220)	$ 542,851	$ 237,838
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depletion and depreciation	401,200	292,951	243,390
Ceiling test and other impairments	3,144,899	0	0
Deferred and current non-cash income taxes	(990)	995	(6)
Unrealized loss (gain) on commodity derivatives	104,190	(130,066)	25,876
Deferred gain on sale of liquids gathering system	(10,553)	(10,553)	(10,553)
(Gain) on sale of property	0	(8,022)	0
Excess tax benefit from stock based compensation	0	0	0
Stock compensation	4,128	5,467	9,767
Other	9,217	4,569	2,252
Net changes in operating assets and liabilities:
Restricted cash	2	2	2
Accounts receivable	65,132	(43,116)	16,565
Prepaid expenses and other	(20,106)	(1,920)	1,180
Other non-current assets	21,112	284	277
Accounts payable	13,815	28,696	(1,400)
Accrued liabilities	1,655	(5,938)	(32,904)
Production taxes payable	(3,312)	15,115	(7,207)
Interest payable	(3,441)	14,233	1,772
Other long-term obligations	(5,770)	6,427	3,296
Current taxes payable	1,580	609	(17,507)
Net cash provided by operating activities	515,538	712,584	472,638
Investing Activities:
Acquisition costs	3,964	(891,075)	(649,801)
Oil and gas property expenditures	(494,025)	(599,913)	(370,662)
Gathering system expenditures	0	(6,842)	(5,510)
Proceeds from sale of property	0	27,944	0
Proceeds from sale of liquids gathering system	0	0	(129)
Proceeds from sale of marketable securities	0	0	0
Change in capital cost accrual	(25,380)	(125,577)	(65,975)
Inventory	3,235	175	(627)
Purchase of property, plant and equipment	(551)	(5,455)	(815)
Net cash used in investing activities	(512,757)	(1,600,743)	(1,093,519)
Financing activities:
Borrowings on long-term debt	1,165,000	1,095,000	1,006,000
Payments on long-term debt	(1,153,000)	(1,037,000)	(823,000)
Proceeds from issuance of Senior Notes	0	850,000	450,000
Deferred financing costs	6	(13,245)	(8,958)
Repurchased shares/net share settlements	(2,514)	(9,111)	(5,429)
Shares re-issued from treasury	0	0	0
Excess tax benefit from stock based compensation	0	0	0
Payment of contingent consideration	(17,049)	0	0
Proceeds from exercise of options	0	770	11
Net cash provided by (used in) financing activities	(7,557)	886,414	618,624
(Decrease)/increase in cash during the period	(4,776)	(1,745)	(2,257)
Cash and cash equivalents, beginning of period	8,919	10,664	12,921
Cash and cash equivalents, end of period	4,143	8,919	10,664
Cash paid for:
Interest	169,867	108,889	99,542
Income taxes	0	1,752	13,843
Non Cash Investing Activities Oil And Gas Properties	$ 0	$ 20,000	$ 12,651