Income Taxes - Operating Loss and Tax Credit Carryforwards (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss and Tax Credit Carryforwards [Line Items]
Increase in valuation allowance		$ 58,500	$ 16,400
Recognized tax benefit		49,969	(46,525)	$ (22,459)
Portion of operating loss carryforwards related to stock options		463,600
Unrecognized tax benefits		81,000	66,508	$ 43,735
Internal Revenue Service (IRS) [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Operating loss carryforwards		1,217,500
State and Local Jurisdiction [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Operating loss carryforwards		572,500
Out-of-State Income Tax Jurisdiction [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Operating loss carryforwards		1,234,000
The American Taxpayer Relief Act of 2012 [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Recognized tax benefit			$ 15,100
Extension of federal research credit			1 year
Research Tax Credit Carryforward [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Recognized tax benefit		20,400
Research Tax Credit Carryforward [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Tax credit carryforward amounts, subject to expiration		113,800
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Tax credit carryforward amounts, not subject to expiration		$ 107,800
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member]
Operating Loss and Tax Credit Carryforwards [Line Items]
Cash paid for settlement with taxing authority	$ 400
Recognized tax benefit for settlement with taxing authority	$ 5,900