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Summary of Significant Accounting Policies - Corrections (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2014	Jan. 31, 2010
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount										$ (27,481)	$ (230,700)	$ (9,800)	$ (5,400)
Deferred tax assets acquired															$ 27,500
Net income	$ 6,341	$ 199,165	$ 23,564	$ 754	$ 7,055	$ 1,280	$ 1,592	$ 2,097			229,824	12,024	11,420
Comprehensive income											$ 229,792	$ 14,063	$ 14,334
Net income, basic (in usd per share)	$ (0.32)	$ (10.01)	$ (1.19)	$ (0.04)	$ (0.35)	$ (0.06)	$ (0.08)	$ (0.10)			$ (11.61)	$ (0.59)	$ (0.56)
Net income, diluted (in USD per share)	$ (0.29)	$ (9.28)	$ (1.11)	$ (0.04)	$ (0.34)	$ (0.06)	$ (0.07)	$ (0.10)			$ (10.83)	$ (0.56)	$ (0.55)
Long-term deferred tax assets	$ 189,083										$ 189,083
Income tax (expense) benefit	514	$ 191,881	$ (265)	$ (15)	$ (280)	$ (124)	$ 47	$ (53)			192,115	$ (410)	$ (374)
Current debt issuance costs	0				809						0	809
Long-term debt issuance costs	0				3,388						0	3,388
Assets	503,061				258,029						503,061	258,029
2019 convertible senior notes, net	201,985										201,985
Liabilities, Current	222,821				22,779						222,821	22,779
Convertible debt, noncurrent	0										0
Liabilities	226,151				233,621						226,151	233,621
Carrying value of equity component	39,628										39,628
Additional Paid in Capital	661,850				680,660						661,850	680,660
Retained Earnings (Accumulated Deficit)	(429,491)				(659,315)						(429,491)	(659,315)
Stockholders' Equity Attributable to Parent	237,282				26,318						237,282	26,318
Liabilities and Equity	503,061				258,029						503,061	258,029
Current contingent liabilities	10,414				$ 6,796						10,414	$ 6,796
Previously Reported Understatement
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		2,100								2,100
Long-term deferred tax assets	2,100										2,100
Income tax (expense) benefit		2,100								$ 2,100
Understatement as percent of previously reported EPS (percent)										1.00%
Current contingent liabilities			600						$ 600
Previously Reported Overstatement
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income			$ 600						$ 600
Net income, basic (in usd per share)			$ (0.03)						$ (0.03)
Impact of Correction of Immaterial Errors
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		$ (600)
Net income, basic (in usd per share)		$ 0.03
Impact of Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income, basic (in usd per share)										$ 0.11
Net income, diluted (in USD per share)										$ 0.10
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income											(27,481)
Comprehensive income											$ (27,481)
Net income, basic (in usd per share)											$ 1.39
Net income, diluted (in USD per share)											$ 1.29
Long-term deferred tax assets	(27,481)										$ (27,481)
Income tax (expense) benefit											27,481
Current debt issuance costs	0										0
Long-term debt issuance costs	0										0
Assets	(27,481)										(27,481)
2019 convertible senior notes, net	205,372										205,372
Liabilities, Current	205,372										205,372
Convertible debt, noncurrent	(205,372)										(205,372)
Carrying value of equity component	39,628										39,628
Additional Paid in Capital	(39,628)										(39,628)
Retained Earnings (Accumulated Deficit)	(27,481)										(27,481)
Stockholders' Equity Attributable to Parent	(67,109)										(67,109)
Liabilities and Equity	(27,481)										(27,481)
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income											257,305
Comprehensive income											$ 257,273
Net income, basic (in usd per share)											$ (13.00)
Net income, diluted (in USD per share)											$ (12.12)
Long-term deferred tax assets	216,564										$ 216,564
Income tax (expense) benefit											219,596
Current debt issuance costs	860										860
Long-term debt issuance costs	2,527										2,527
Assets	533,929										533,929
2019 convertible senior notes, net	0										0
Liabilities, Current	20,836										20,836
Convertible debt, noncurrent	205,372										205,372
Liabilities	229,538										229,538
Carrying value of equity component	0										0
Additional Paid in Capital	701,478										701,478
Retained Earnings (Accumulated Deficit)	(402,010)										(402,010)
Stockholders' Equity Attributable to Parent	304,391										304,391
Liabilities and Equity	533,929										533,929
Senior Notes | 2019 Convertible Senior Notes
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Long-term debt issuance costs														$ 4,500
Convertible debt, noncurrent														$ 192,500
Carrying value of equity component	51,300										$ 51,300
Stock price trigger threshold (percent)											130.00%
Adoption of ASU 2015-03
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Long-term deferred tax assets	0										$ 0
Current debt issuance costs	(860)										(860)
Long-term debt issuance costs	(2,527)										(2,527)
Assets	(3,387)										(3,387)
2019 convertible senior notes, net	(3,387)										(3,387)
Liabilities, Current	(3,387)										(3,387)
Convertible debt, noncurrent	0										0
Liabilities	(3,387)										(3,387)
Carrying value of equity component	0										0
Additional Paid in Capital	0										0
Retained Earnings (Accumulated Deficit)	0										0
Stockholders' Equity Attributable to Parent	0										0
Liabilities and Equity	$ (3,387)										$ (3,387)

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