Commitments and Contingencies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Future minimum lease payments under noncancelable operating leases
2012	$ 2,673,000		$ 2,673,000
2013	4,659,000		4,659,000
2014	3,907,000		3,907,000
2015	2,898,000		2,898,000
2016	1,558,000		1,558,000
Thereafter	9,503,000		9,503,000
Total minimum lease payments	25,198,000		25,198,000
Rent expense	$ 1,100,000	$ 800,000	$ 2,300,000	$ 1,600,000