Lease Arrangements (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Capital Leases
2014	$ 7,664,000
2015	6,066,000
2016	4,696,000
2017	3,026,000
2018	1,329,000
Thereafter	71,000
Total minimum lease payments	22,852,000
Less amounts representing interest	2,612,000
Present value of minimum lease payments	20,240,000
Less current maturities	6,516,000	6,052,000
Total long-term obligations under capital leases	13,724,000	11,632,000
Operating Leases
2014	66,445,000
2015	53,934,000
2016	36,717,000
2017	24,296,000
2018	15,060,000
Thereafter	12,840,000
Total minimum lease payments	209,292,000
Leased vehicles
Out-of-period adjustment relating to capital lease accounting
Minimum lease term required under master lease agreement	12 months
Current minimum lease term per vehicle	60 months
Decrease in pre-tax income due to out-of-period adjustment relating to capital lease accounting		700,000
Decrease in pre-tax income due to out-of-period adjustment relating to capital lease accounting, after tax		400,000
Increase in net property and equipment due to out-of-period adjustment relating to capital lease accounting		16,500,000
Increase in capital lease obligations due to out-of-period adjustment relating to capital lease accounting		17,300,000
Impact to the cash flow statement due to increased depreciation and payments on capital lease obligations		$ 5,900,000