Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Leases [Abstract]
Remaining term of operating leases (in years)	6Y
Total rental expense under operating leases	$ 5,400,000		$ 6,300,000	$ 6,800,000
Minimum future operating lease payments [Abstract]
2012	4,379,000
2013	3,151,000
2014	1,098,000
2015	294,000
2016 and thereafter	137,000
Total	9,059,000	[1]
Minimum future sublease rentals	$ 525,000

[1] Minimum payments have not been reduced by minimum sublease rentals of $525 thousand due in the future under noncancelable subleases.