Commitments, Guarantees, and Contingencies (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2008
Operating Leases, Rent Expense		$ 6,914,000	$ 6,615,000	$ 5,769,000
Operating Lease Area					60,000
Deferred Rent Credit			1,041,000
Net Gain On Lease	1,041,000
Letters of Credit Outstanding, Amount		196,000
Loss Contingency, Damages Sought, Value		10,000
Other Commitment, Due in Next Twelve Months		3,245,000
Loss Contingency, Settlement Agreement, Consideration		$ 65,000