Significant Accounting Policies, Stock-Based Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	May. 31, 2015
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 14,997	$ 8,118	$ 41,907	$ 22,894
Stock Option [Member]
Stock-based Compensation Expense [Abstract]
Unrecognized estimated non-cash stock-based compensation expense	53,100		$ 53,100
Weighted average period of amortization			1 year 3 months 18 days
RSUs [Member]
Stock-based Compensation Expense [Abstract]
Vesting period			4 years
Unrecognized estimated non-cash stock-based compensation expense	20,200		$ 20,200
Weighted average period of amortization			1 year 4 months 24 days
RSUs [Member] | Employees [Member]
Stock-based Compensation Expense [Abstract]
Weighted-average grant date fair value (in dollars per share)			$ 67.57
RSUs [Member] | Board of Directors [Member]
Stock-based Compensation Expense [Abstract]
Weighted-average grant date fair value (in dollars per share)			$ 57.16
2011 Equity Incentive Plan [Member]
Amendments to Equity Plans [Abstract]
Number of shares authorized (in shares)					11.0	5.5
2002 Nonemployee Directors Stock Option Plan [Member]
Amendments to Equity Plans [Abstract]
Number of shares authorized (in shares)					2.0	1.2
Research, Development and Patent Expenses [Member]
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	11,297	6,606	$ 32,248	18,879
General and Administrative [Member]
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 3,700	$ 1,512	$ 9,659	$ 4,015