Internally Developed Capitalized Software - Summary of Internally Developed Capitalized Software (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Movement in Property, Plant and Equipment [Roll Forward]
Depreciation expense	$ (1,300)	$ (1,657)
Net Carrying Amount, Beginning Balance	10,611
Net Carrying Amount, Ending Balance	10,453
Depreciation Expense Related to Capitalized Software
Movement in Property, Plant and Equipment [Roll Forward]
Gross Carrying Amount, Beginning Balance	15,015	14,582
Additions	729
Gross Carrying Amount, Ending Balance	15,744	14,582
Accumulated Depreciation, Beginning Balance	(7,931)	(6,880)
Depreciation expense	(932)	(919)
Accumulated Depreciation, Ending Balance	(8,863)	(7,799)
Net Carrying Amount, Beginning Balance	7,084	7,702
Net Carrying Amount, Ending Balance	$ 6,881	$ 6,783