Leasing (Future Minimum Lease Payments for Operating and Capital Leases) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
2013	$ 240,274
2014	226,780
2015	203,155
2016	178,167
2017	154,270
Thereafter	840,790
Total	1,843,436
Non-Related Parties [Member] | Operating Lease Expense [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	235,601
2014	222,216
2015	198,700
2016	174,171
2017	150,970
Thereafter	829,172
Total	1,810,830
Non-Related Parties [Member] | Capital Lease Expense [Member]
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	234
2014	77
2015	25
2016	0
2017	0
Thereafter	0
Total	336
Related Parties [Member] | Operating Lease Expense [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	4,439
2014	4,487
2015	4,430
2016	3,996
2017	3,300
Thereafter	11,618
Total	$ 32,270