Lease Commitments (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 sqft	Dec. 31, 2011	Dec. 31, 2010
Lease Commitments (Textual) [Abstract]
Termination of noncancellable lease arrangements	$ 6.2	$ 6.7	$ 6.2
Office space in square feet	58,000
Liabilities relating to lease obligations	2.0
Accounts payable and accrued expenses	1.1
Other long-term liabilities	$ 0.9