Summary of Significant Accounting Policies - Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2016
Furniture, Fixtures and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment useful life	5 years
Computer Equipment [Member]
Property and Equipment [Line Items]
Property and equipment useful life	3 years
Software and Capitalized Software Costs [Member]
Property and Equipment [Line Items]
Property and equipment useful life	3 years
Buildings [Member]
Property and Equipment [Line Items]
Property and equipment useful life	30 years
Leasehold Improvements [Member] | Minimum [Member]
Property and Equipment [Line Items]
Property and equipment useful life	3 years
Leasehold Improvements [Member] | Maximum [Member]
Property and Equipment [Line Items]
Property and equipment useful life	5 years
Rental Clocks [Member]
Property and Equipment [Line Items]
Property and equipment useful life	5 years
Vehicles [Member]
Property and Equipment [Line Items]
Property and equipment useful life	3 years