Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (2,343,309)	$ (694,426)	$ (510,763)
Adjustments to reconcile net loss to net cash used in operating activities:
Dry hole costs and impairments	1,967,180	462,234	236,930
Equity-based compensation	14,889	26,297	31,742
Accretion expense	550	99
Depreciation and amortization	21,983	3,881	4,584
Loss on derivatives	2,505
(Accretion of discount) amortization of premium on investments	(242)	14,483	20,925
Amortization of debt discount	77,041	89,662	71,330
Other	(213)	(1,555)	12
Changes in operating assets and liabilities:
Joint interest and other receivables	44,679	(151,334)	64,679
Other current assets	71,323	(27,528)	20,453
Trade and other accounts payable	20,138	2,681	(64,369)
Accrued liabilities	(62,058)	272,065	46,749
Accrued contract amendment costs	19,582
Other	287	1,795	15,968
Net cash flows used in operating activities	(165,665)	(1,646)	(61,760)
Cash flows from investing activities
Additions to oil and natural gas properties	(687,892)	(915,861)	(748,656)
Capital expenditures for other property	(3,479)	(4,808)	(4,074)
Proceeds from maturity of investment securities	3,390,112	1,999,421	2,350,705
Purchase of investment securities	(2,545,911)	(1,192,873)	(2,739,134)
Net cash flows provided by (used in) investing activities	152,830	(114,121)	(1,141,159)
Cash flows from financing activities
Proceeds from issuance of long-term debt	490,000
Proceeds from debt offering, net of costs			1,269,778
Payment of debt issuance costs		(4,068)
Proceeds from exercise of stock options			33
Payments for common stock withheld for taxes on equity-based compensation			(631)
Net cash flows provided by (used in) financing activities	490,000	(4,068)	1,269,180
Increase (decrease) in cash, cash equivalents and restricted cash	477,165	(119,835)	66,261
Cash, cash equivalents and restricted cash, beginning of year	138,886	258,721	192,460
Cash, cash equivalents and restricted cash, end of year	$ 616,051	$ 138,886	$ 258,721