Net Product Sales (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Revenue Disclosure [Line Items]
Branded Prescription Drug Fee	$ 40,600,000
Net product sales	448,844,000	367,118,000	1,229,244,000	1,019,751,000
Activity of Sales Related Deductions [Roll Forward]
Balance	22,795,000		22,795,000		24,601,000
Provision related to current period sales			78,156,000
Credits/payments			(79,962,000)
Rebates and Chargebacks
Activity of Sales Related Deductions [Roll Forward]
Balance	3,792,000		3,792,000		4,400,000
Provision related to current period sales			23,265,000
Credits/payments			(23,873,000)
Distribution Related Fees
Activity of Sales Related Deductions [Roll Forward]
Balance	18,474,000		18,474,000		19,663,000
Provision related to current period sales			53,689,000
Credits/payments			(54,878,000)
Other Sales Related Deductions
Activity of Sales Related Deductions [Roll Forward]
Balance	529,000		529,000		538,000
Provision related to current period sales			1,202,000
Credits/payments			(1,211,000)
Customer concentration risk | Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	72.00%	75.00%	75.00%	76.00%
EYLEA
Revenue Disclosure [Line Items]
Net product sales	445,000,000	363,100,000	1,218,800,000	1,006,800,000
ARCALYST
Revenue Disclosure [Line Items]
Net product sales	$ 3,800,000	$ 4,000,000	$ 10,400,000	$ 12,900,000