Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Leases, Future Minimum Payments Due [Abstract]
2012	$ 6,668,000
2013	6,665,000
2014	6,609,000
2015	6,609,000
2016	6,608,000
Thereafter	3,795,000
Total	36,954,000
Operating Leases, Rent Expense	$ 7,400,000	$ 7,100,000	$ 7,100,000