Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	$ 895,219	$ 820,253
Less - accumulated depreciation and amortization	(387,466)	(352,212)
Total property and equipment, net	507,753	468,041
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	72,651	64,495
Buildings and improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	156,417	152,812
Leasehold improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	213,272	193,274
Furniture and equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	325,244	296,789
Software [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	46,366	39,987
Buildings held under capital leases [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	58,984	59,555
Equipment held under capital leases [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	55	875
Less - accumulated depreciation and amortization	(19,100)	(17,000)
Construction in Progress [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	$ 22,230	$ 12,466