Direct Financing Leases and Other Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Direct Financing Leases And Other Assets [Abstract]
Direct financing leases, net	$ 315,528	$ 280,988
Investments held in Rabbi Trusts	22,426	18,696
Insurance receivables	21,695	15,488
Debt issuance costs	16,323	16,106
Prepaid pension asset	6,090	257
Contract incentives	17,613	17,524
Interest rate swap agreement	15,412	21,843
Other	19,503	22,783
Total	$ 434,590	$ 393,685