Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 15,949,000	$ 10,600,000	$ 8,195,000
Remaining unamortized capitalized internal use software costs	1,052,000	0
Software [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 213,000	$ 238,000	$ 459,000