Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Accounts Payable and Accrued Expenses
Accrued research payables	$ 45,997	$ 50,721
Accrued compensation and benefits	21,869	50,666
Trade payables	18,904	17,790
Deferred revenue	15,242	15,493
Accrued restructuring	7,914	11,708
Deferred compensation	5,079	7,579
Accrued transaction processing	3,034	2,986
Other	25,047	24,281
Total	$ 143,086	$ 181,224