Restructuring Expense (Details) (USD $)	3 Months Ended								12 Months Ended				96 Months Ended	12 Months Ended			1 Months Ended		12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2003	Dec. 31, 2011	Dec. 31, 2003 Lease restructuring and other operating lease expense	Dec. 31, 2003 Employee severance, benefits and related costs	Dec. 31, 2003 Leasehold improvements and asset impairments	Jun. 30, 2003 Kendall Square Facility squarefeet	Jan. 31, 2003 Kendall Square Facility Y	Dec. 31, 2006 Kendall Square Facility squarefeet	Dec. 31, 2003 Kendall Square Facility
Restructuring Expense
Accrued restructuring expense, current portion	$ 4,932,000				$ 5,497,000				$ 4,932,000	$ 5,497,000			$ 4,932,000
Accrued restructuring expense, excluding current portion	21,381,000				24,098,000				21,381,000	24,098,000			21,381,000
Lease restructuring expense												78,700,000
Lease operating expense												6,000,000
Kendall Square Lease
Leased area (in square feet)																	290,000
Lease term (in years)																		15
Occupied leased area (in square feet)																			120,000
Discount rate, lease restructuring liability (as a percent)																				10.00%
Restructuring activities
Lease restructuring liability at beginning of period				29,595,000				34,017,000	29,595,000	34,017,000	34,064,000		69,526,000
Restructuring expense	992,000	(419,000)	741,000	760,000	(2,257,000)	866,000	2,112,000	780,000	2,074,000	1,501,000	6,240,000	91,824,000	60,635,000	84,726,000	2,616,000	4,482,000
Cash payments									(14,904,000)	(14,759,000)	(14,924,000)	(17,816,000)	(148,844,000)	(15,200,000)	(2,616,000)
Non-cash write-off in 2003												(4,482,000)				(4,482,000)
Lease restructuring liability at end of period	$ 26,313,000				$ 29,595,000				$ 26,313,000	$ 29,595,000	$ 34,017,000	$ 69,526,000	$ 26,313,000	$ 69,526,000