Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts Payable and Accrued Expenses
Accrued research payables	$ 53,239	$ 38,591
Accrued compensation and benefits	32,376	39,762
Trade payables	19,332	22,624
Accrued rent	17,032	10,947
Deferred revenue	13,512	12,177
Accrued restructuring	6,112	12,295
Deferred compensation	4,520	4,650
Accrued transaction processing	3,025	3,359
Other	25,645	20,657
Total	$ 174,793	$ 165,062