Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounts Payable and Accrued Expenses
Accrued research payables	$ 41,987	$ 38,591
Accrued compensation and benefits	20,120	39,762
Trade payables	17,923	22,624
Accrued rent	15,881	10,947
Deferred revenue	14,248	12,177
Accrued restructuring	8,486	12,295
Deferred compensation	4,715	4,650
Accrued transaction processing	3,363	3,359
Other	21,329	20,657
Total	$ 148,052	$ 165,062