Condensed Consolidating Financial Statements - Schedule of Condensed Consolidating Statement of Cash Flows (Detail) - USD ($)						3 Months Ended								12 Months Ended
	Oct. 21, 2016	Apr. 01, 2016	Feb. 02, 2016	Mar. 09, 2015	Mar. 05, 2014	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income						$ (54,688,000)	$ (33,942,000)	$ (89,931,000)	$ (64,455,000)	$ 3,968,000	$ 27,055,000	$ (53,230,000)	$ (18,041,000)	$ (243,016,000)	$ (40,248,000)	$ 506,877,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in loss of subsidiaries														0	0	0
Depreciation, depletion and amortization														476,331,000	485,322,000	412,334,000
Gain on extinguishment of debt														(4,741,000)	0	0
Loss on sale of properties														1,303,000	0	(186,999,000)
Impairment														4,684,000	46,109,000	47,238,000
Deferred income taxes														(128,538,000)	(16,114,000)	307,457,000
Derivative instruments														105,317,000	(210,376,000)	(327,011,000)
Stock-based compensation expenses														24,103,000	25,272,000	21,302,000
Deferred financing costs amortization and other														14,334,000	12,299,000	11,028,000
Working capital and other changes:
Change in accounts receivable, net														(11,923,000)	108,461,000	16,702,000
Change in inventory														254,000	6,873,000	(3,776,000)
Change in prepaid expenses														(295,000)	1,828,000	(3,199,000)
Change in other current assets														(305,000)	6,489,000	(6,135,000)
Change in other assets														(151,000)	(950,000)	114,000
Change in accounts payable and accrued liabilities														(13,839,000)	(71,617,000)	76,723,000
Change in other current liabilities														4,490,000	6,500,000	0
Change in other liabilities														10,000	(33,000)	(139,000)
Net cash provided by operating activities														228,018,000	359,815,000	872,516,000
Cash flows from investing activities:
Capital expenditures														(426,256,000)	(819,847,000)	(1,354,281,000)
Acquisitions of oil and gas properties														(781,522,000)	(28,817,000)	(46,247,000)
Proceeds from sale of properties		$ 12,300,000			$ 324,900,000									12,333,000	1,075,000	324,852,000
Costs related to sale of properties														(310,000)	0	(2,337,000)
Derivative settlements														121,977,000	370,410,000	6,774,000
Advances from joint interest partners														2,950,000	(1,969,000)	(6,213,000)
Net cash used in investing activities														(1,070,828,000)	(479,148,000)	(1,077,452,000)
Cash flows from financing activities:
Proceeds from revolving credit facility														1,407,000,000	630,000,000	620,000,000
Principal payments on revolving credit facility														(1,182,000,000)	(992,000,000)	(455,570,000)
Repurchase of senior unsecured notes														(435,907,000)	0	0
Proceeds from issuance of senior unsecured convertible notes														300,000,000	0	0
Deferred financing costs														(9,127,000)	(14,632,000)	(99,000)
Proceeds from sale of common stock	$ 583,900,000		$ 182,800,000	$ 462,800,000										766,670,000	462,833,000	0
Purchases of treasury stock														(2,330,000)	(2,949,000)	(5,309,000)
Investment in / capital contributions from subsidiaries														0	0	0
Other														0	0	(176,000)
Net cash provided by financing activities														844,306,000	83,252,000	158,846,000
Increase (decrease) in cash and cash equivalents														1,496,000	(36,081,000)	(46,090,000)
Beginning of period									9,730,000				45,811,000	9,730,000	45,811,000	91,901,000
End of period						11,226,000				9,730,000				11,226,000	9,730,000	45,811,000
Intercompany Eliminations
Cash flows from operating activities:
Net income														140,978,000	(69,986,000)	(613,601,000)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in loss of subsidiaries														(140,978,000)	69,986,000	613,601,000
Depreciation, depletion and amortization														0	0	0
Gain on extinguishment of debt														0
Loss on sale of properties														0		0
Impairment														0	0	0
Deferred income taxes														0	0	0
Derivative instruments														0	0	0
Stock-based compensation expenses														0	0	0
Deferred financing costs amortization and other														0	0	0
Working capital and other changes:
Change in accounts receivable, net														30,883,000	156,496,000	82,370,000
Change in inventory														0	0	0
Change in prepaid expenses														0	0	0
Change in other current assets														0	0	0
Change in other assets														0	0	0
Change in accounts payable and accrued liabilities														(30,883,000)	(156,496,000)	(82,370,000)
Change in other current liabilities														0	0
Change in other liabilities														0	0	0
Net cash provided by operating activities														0	0	0
Cash flows from investing activities:
Capital expenditures														0	0	0
Acquisitions of oil and gas properties														0	0	0
Proceeds from sale of properties														0	0	0
Costs related to sale of properties														0		0
Derivative settlements														0	0	0
Advances from joint interest partners														0	0	0
Net cash used in investing activities														0	0	0
Cash flows from financing activities:
Proceeds from revolving credit facility														0	0	0
Principal payments on revolving credit facility														0	0	0
Repurchase of senior unsecured notes														0
Proceeds from issuance of senior unsecured convertible notes														0
Deferred financing costs														0	0	0
Proceeds from sale of common stock														0	0
Purchases of treasury stock														0	0	0
Investment in / capital contributions from subsidiaries														0	0	0
Other																0
Net cash provided by financing activities														0	0	0
Increase (decrease) in cash and cash equivalents														0	0	0
Beginning of period									0				0	0	0	0
End of period						0				0				0	0	0
Parent/ Issuer
Cash flows from operating activities:
Net income														(243,016,000)	(40,248,000)	506,877,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in loss of subsidiaries														140,978,000	(69,986,000)	(613,601,000)
Depreciation, depletion and amortization														0	0	0
Gain on extinguishment of debt														(4,741,000)
Loss on sale of properties														0		0
Impairment														0	0	0
Deferred income taxes														(48,796,000)	(55,857,000)	(64,029,000)
Derivative instruments														0	0	0
Stock-based compensation expenses														23,346,000	24,762,000	20,701,000
Deferred financing costs amortization and other														9,107,000	4,964,000	4,549,000
Working capital and other changes:
Change in accounts receivable, net														(250,737,000)	(482,000)	(11,000)
Change in inventory														0	0	0
Change in prepaid expenses														3,000	19,000	21,000
Change in other current assets														0	0	0
Change in other assets														100,000	0	0
Change in accounts payable and accrued liabilities														(230,518,000)	156,039,000	84,044,000
Change in other current liabilities														0	0
Change in other liabilities														0	0	0
Net cash provided by operating activities														(604,274,000)	19,211,000	(61,449,000)
Cash flows from investing activities:
Capital expenditures														0	0	0
Acquisitions of oil and gas properties														0	0	0
Proceeds from sale of properties														0	0	0
Costs related to sale of properties														0		0
Derivative settlements														0	0	0
Advances from joint interest partners														0	0	0
Net cash used in investing activities														0	0	0
Cash flows from financing activities:
Proceeds from revolving credit facility														0	0	0
Principal payments on revolving credit facility														0	0	0
Repurchase of senior unsecured notes														(435,907,000)
Proceeds from issuance of senior unsecured convertible notes														300,000,000
Deferred financing costs														(8,197,000)	(11,045,000)	0
Proceeds from sale of common stock														766,670,000	462,833,000
Purchases of treasury stock														(2,330,000)	(2,949,000)	(5,309,000)
Investment in / capital contributions from subsidiaries														(16,573,000)	(468,049,000)	33,433,000
Other																(176,000)
Net cash provided by financing activities														603,663,000	(19,210,000)	27,948,000
Increase (decrease) in cash and cash equivalents														(611,000)	1,000	(33,501,000)
Beginning of period									777,000				776,000	777,000	776,000	34,277,000
End of period						166,000				777,000				166,000	777,000	776,000
Combined Guarantor Subsidiaries
Cash flows from operating activities:
Net income														(140,978,000)	69,986,000	613,601,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in loss of subsidiaries														0	0	0
Depreciation, depletion and amortization														476,331,000	485,322,000	412,334,000
Gain on extinguishment of debt														0
Loss on sale of properties														1,303,000		(186,999,000)
Impairment														4,684,000	46,109,000	47,238,000
Deferred income taxes														(79,742,000)	39,743,000	371,486,000
Derivative instruments														105,317,000	(210,376,000)	(327,011,000)
Stock-based compensation expenses														757,000	510,000	601,000
Deferred financing costs amortization and other														5,227,000	7,335,000	6,479,000
Working capital and other changes:
Change in accounts receivable, net														207,931,000	(47,553,000)	(65,657,000)
Change in inventory														254,000	6,873,000	(3,776,000)
Change in prepaid expenses														(298,000)	1,809,000	(3,220,000)
Change in other current assets														(305,000)	6,489,000	(6,135,000)
Change in other assets														(251,000)	(950,000)	114,000
Change in accounts payable and accrued liabilities														247,562,000	(71,160,000)	75,049,000
Change in other current liabilities														4,490,000	6,500,000
Change in other liabilities														10,000	(33,000)	(139,000)
Net cash provided by operating activities														832,292,000	340,604,000	933,965,000
Cash flows from investing activities:
Capital expenditures														(426,256,000)	(819,847,000)	(1,354,281,000)
Acquisitions of oil and gas properties														(781,522,000)	(28,817,000)	(46,247,000)
Proceeds from sale of properties														12,333,000	1,075,000	324,852,000
Costs related to sale of properties														(310,000)		(2,337,000)
Derivative settlements														121,977,000	370,410,000	6,774,000
Advances from joint interest partners														2,950,000	(1,969,000)	(6,213,000)
Net cash used in investing activities														(1,070,828,000)	(479,148,000)	(1,077,452,000)
Cash flows from financing activities:
Proceeds from revolving credit facility														1,407,000,000	630,000,000	620,000,000
Principal payments on revolving credit facility														(1,182,000,000)	(992,000,000)	(455,570,000)
Repurchase of senior unsecured notes														0
Proceeds from issuance of senior unsecured convertible notes														0
Deferred financing costs														(930,000)	(3,587,000)	(99,000)
Proceeds from sale of common stock														0	0
Purchases of treasury stock														0	0	0
Investment in / capital contributions from subsidiaries														16,573,000	468,049,000	(33,433,000)
Other																0
Net cash provided by financing activities														240,643,000	102,462,000	130,898,000
Increase (decrease) in cash and cash equivalents														2,107,000	(36,082,000)	(12,589,000)
Beginning of period									$ 8,953,000				$ 45,035,000	8,953,000	45,035,000	57,624,000
End of period						$ 11,060,000				$ 8,953,000				$ 11,060,000	$ 8,953,000	$ 45,035,000