Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 126,050	$ 126,952
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(83,416)	(80,535)
Property, Plant and Equipment, Net	42,634	46,417
Computers and Software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	11,042	10,986
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	7,343	7,391
Laboratory Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	36,065	37,030
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	9,991	9,934
Buildings
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	58,945	58,947
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,664	$ 2,664