Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net loss	$ (201,366)	$ (449,228)
Adjustments to reconcile net loss to net cash provided by operating activities
Unrealized loss on derivatives	30,261	25,356
Depletion, depreciation and amortization	90,185	143,477
Accretion of asset retirement obligations	828	427
Full-cost ceiling impairment	158,633	581,874
Stock-based compensation expense	9,138	6,886
Deferred income tax benefit		(148,750)
Amortization of debt issuance cost	899	551
Net (gain) loss on asset sales and inventory impairment	(3,140)	97
Changes in operating assets and liabilities
Accounts receivable	(7,782)	1,997
Lease and well equipment inventory	(669)	(225)
Prepaid expenses	(74)	(329)
Other assets	480	665
Accounts payable, accrued liabilities and other current liabilities	9,710	16,863
Royalties payable	5,225	6,898
Advances from joint interest owners	3,147	306
Income taxes payable	(2,848)	(444)
Other long-term liabilities	3,835	(497)
Net cash provided by operating activities	96,462	185,924
Investing activities
Oil and natural gas properties capital expenditures	(288,175)	(334,951)
Expenditures for other property and equipment	(57,148)	(46,738)
Proceeds from Sale of Oil and Gas Property and Equipment	5,173	0
Business combination, net of cash acquired	0	(24,028)
Restricted cash	43,098	0
Restricted cash in less-than-wholly-owned subsidiaries	(544)	158
Net cash used in investing activities	(297,596)	(405,559)
Financing activities
Repayments of borrowings	0	(476,982)
Borrowings under Credit Agreement	65,000	125,000
Proceeds from issuance of senior unsecured notes	0	400,000
Cost to issue senior unsecured notes	0	(9,479)
Proceeds from issuance of common stock	142,350	188,720
Cost to issue equity	(830)	(1,151)
Proceeds from stock options exercised	0	10
Capital commitments from non-controlling interest owners in less-than-wholly-owned subsidiaries	0	562
Taxes paid related to net share settlement of stock-based compensation	(1,552)	(1,565)
Net cash provided by financing activities	204,968	225,115
Increase in cash	3,834	5,480
Cash at beginning of period	16,732	8,407
Cash at end of period	$ 20,566	$ 13,887