Commitments and Contingencies (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitments and Contingencies (Textual) [Abstract]
Interest range, Minimum	3.60%
Interest range, Maximum	19.60%
Rent expense on operating leases	$ 50,908	$ 46,411	$ 47,798
Contingent rental expense	1,789	1,426	1,767
Interest expense	1,560	1,205	1,394
Deduction in general insurance policy liability per claim	150
Workers compensation	300
Accrued claims related to self Insurance general liability and workers Compensation Insurance liability	$ 1,911	$ 1,767