Restructuring (Details) (USD $)	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011	Dec. 31, 2010
Restructuring.
Expected number of reduction in workforce, greater than		60
Restructuring related costs recognized				$ 2,200,000
Components of restructuring expenses and reserve
Accrued restructuring, beginning of period	537,000		1,324,000
Employee severance, benefits and related costs	49,000		177,000
Payments	(345,000)		(1,155,000)
Other adjustments	(17,000)		(122,000)
Accrued restructuring, end of period	$ 224,000	$ 1,324,000	$ 224,000	$ 1,324,000