Restructuring (Details) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended
	Nov. 30, 2011	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2012 Employee severance and benefits	Dec. 31, 2011 Employee severance and benefits	Jun. 30, 2012 Employee severance and benefits	Jun. 30, 2012 Manufacturing facility divestiture
Restructuring Cost and Reserve
Total restructuring charges expected to be incurred			$ 1,600,000			$ 1,000,000
Percentage of reduction in workforce	25.00%
Restructuring charges recognized				500,000	3,500,000		600,000
Components of restructuring expenses and reserve
Accrued restructuring, beginning of period		1,763,000	2,366,000
Employee severance, benefits and related costs		493,000	578,000
Payments		(518,000)	(1,127,000)
Reclassification to inventory reserve		(575,000)	(575,000)
Other adjustments		565,000	486,000
Accrued restructuring, end of period		$ 1,728,000	$ 1,728,000