Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,032,566		$ 1,032,566		$ 1,029,441
Less accumulated depreciation	(583,949)		(583,949)		(572,944)
Property and equipment, net	448,617		448,617		456,497
Depreciation expense	22,500	$ 22,400	45,900	$ 44,200
Impairment losses	12,200	$ 100	12,234	$ 100
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,476		7,476		7,476
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,487		6,487		6,487
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	72,951		72,951		68,851
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	899,840		899,840		902,482
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	43,230		43,230		43,476
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,582		$ 2,582		$ 669