Restructuring Expense (Details) (Kendall Square Facility)	1 Months Ended		12 Months Ended
	Jun. 30, 2003 sqft	Jan. 31, 2003 years	Dec. 31, 2006 sqft	Dec. 31, 2003
Kendall Square Facility
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%