Property and Equipment (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment [Abstract]
Property and equipment		$ 818,496	$ 784,644
Less: accumulated depreciation		(350,315)	(331,040)
Property and equipment, net		468,181	453,604
Depreciation expense		62,500	61,700	$ 56,400
Impairment charges		0	0	$ 48,551
Land [Member]
Property and Equipment [Abstract]
Property and equipment		45,242	44,532
Buildings [Member]
Property and Equipment [Abstract]
Property and equipment		278,779	273,264
Construction in Progress [Member]
Property and Equipment [Abstract]
Property and equipment	[1]	34,954	17,707
Furniture and Fixtures [Member]
Property and Equipment [Abstract]
Property and equipment		146,413	130,591
Computers and Equipment [Member]
Property and Equipment [Abstract]
Property and equipment		137,914	147,806
Leasehold Improvements [Member]
Property and Equipment [Abstract]
Property and equipment		164,963	160,623
Scanners [Member]
Property and Equipment [Abstract]
Property and equipment		8,119	8,040
Vehicles [Member]
Property and Equipment [Abstract]
Property and equipment		2,112	2,081
Internal-Use Software Development Costs [Member]
Property and Equipment [Abstract]
Property and equipment		$ 13,600	$ 10,800

[1] Construction in progress includes $13.6 million and $10.8 million as of December 31, 2020 and 2019, respectively, of eligible capitalized internal-use software development costs which will be reclassified to computers and equipment when placed into service.