Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income (loss) from operations before income taxes
Income (loss) before income taxes	$ 7,556	$ (48,547)	$ (82,848)
Reconciliation of income taxes at the U.S. federal statutory rate to the provision for income taxes
Provision (benefit) at U.S. federal statutory rate	2,645	(16,992)	(28,997)
Unbenefitted net operating losses and tax credits	(29,424)	13,432	18,215
Non-deductible amortization of debt discount	1,087	2,294	6,645
Non-deductible interest expense	122	1	747
Non-deductible debt exchange expense and loss on repurchase of senior notes			7,985
Deferred tax impact of law change			(5,549)
Foreign tax rate differential	21,443
Non-deductible officer compensation	4,696	830	976
Other	456	369	277
Provision (benefit) for income taxes	1,025	(66)	299
Deferred tax assets:
Federal and state net operating loss carry forwards	329,984	504,267
Federal and state research credits	201,151	165,352
Capitalized research and development	13,017	2,475
Deferred revenue and accruals	11,212	15,799
Non-cash compensation	39,034	31,248
Deferred financing obligation	20,328	20,383
Other	3,125	8,306
Total gross deferred tax assets	617,851	747,830
Less valuation allowance for deferred tax assets	(542,936)	(669,168)
Net deferred tax assets	74,915	78,662
Deferred tax liabilities:
Property and equipment	(25,787)	(19,925)
Equity component of 2018 Notes and 2020 Notes	(49,128)	(58,737)
Total gross deferred tax liabilities	(74,915)	(78,662)
Valuation allowance
Increase (decrease) in valuation allowance	(126,200)	(42,200)	(50,000)
Realized tax benefits	106,400
U.S.
Income (loss) from operations before income taxes
Income (loss) before income taxes	110,560	(48,506)	$ (82,848)
Non-U.S.
Income (loss) from operations before income taxes
Income (loss) before income taxes	$ (103,004)	$ (41)