Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,056,099		$ 1,029,441
Less accumulated depreciation	(596,621)		(572,944)
Property and equipment, net	459,478		456,497
Depreciation expense	23,400	$ 21,800
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,476		7,476
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,487		6,487
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	71,559		68,851
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	925,752		902,482
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	43,607		43,476
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,218		$ 669