Leasing (Net Rent Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leases, Rent Expense, Net [Abstract]
Minimum operating lease expense	$ 234,113	$ 226,158	$ 221,540
Contingent rents	744	534	903
Other lease related occupancy costs	10,043	8,821	9,352
Total rent expense	244,900	235,513	231,795
Less: sublease income	4,031	4,616	4,916
Net rent expense	$ 240,869	$ 230,897	$ 226,879