Property and Equipment, Net - Schedule of Property and Equipment and Associated Accumulated Depreciation and Amortization (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property and Equipment [Line Items]
Property and equipment, gross	$ 162,808	$ 151,791
Less: accumulated depreciation and amortization	(59,540)	(53,525)
Property and equipment, net	159,561	147,705
Buildings [Member]
Property and Equipment [Line Items]
Property and equipment, gross	60,647	60,441
Software and Capitalized Software Costs [Member]
Property and Equipment [Line Items]
Property and equipment, gross	49,404	41,996
Computer Equipment [Member]
Property and Equipment [Line Items]
Property and equipment, gross	30,525	27,928
Rental Clocks [Member]
Property and Equipment [Line Items]
Property and equipment, gross	13,627	13,131
Furniture, Fixtures and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment, gross	7,776	7,528
Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and equipment, gross	779	767
Vehicles [Member]
Property and Equipment [Line Items]
Property and equipment, gross	50
Excluded Land and Construction in Process [Member]
Property and Equipment [Line Items]
Property and equipment, net	103,268	98,266
Land [Member]
Property and Equipment [Line Items]
Property and equipment, net	9,013	8,993
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and equipment, net	$ 47,280	$ 40,446