Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	$ 480,200,000	$ 422,200,000
Less accumulated depreciation	(278,800,000)	(238,400,000)
Property and equipment, net	201,395,000	183,793,000
Depreciation expense	35,600,000	27,900,000	28,800,000
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	1,700,000	1,700,000
Leasehold improvements under development [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	3,900,000	2,000,000
Building and improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	52,400,000	47,500,000
Furniture, equipment and software [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	$ 422,200,000	$ 371,000,000