Leasing (Net Rent Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Leases, Rent Expense, Net [Abstract]
Minimum operating lease expense	$ 263,479	$ 254,565	$ 247,039
Contingent rents	947	759	701
Other lease related occupancy costs	12,852	11,688	11,257
Total rent expense	277,278	267,012	258,997
Less: sublease income	4,019	3,984	4,105
Net rent expense	$ 273,259	$ 263,028	$ 254,892