Leases (Net Rent Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Leases, Rent Expense, Net [Abstract]
Minimum operating lease expense	$ 305,613	$ 289,245
Contingent rents	806	1,049
Other lease related occupancy costs	14,449	12,478
Total rent expense	320,868	302,772
Less: sublease income	3,585	4,158
Net rent expense	$ 317,283	$ 298,614