Fair Value Measurements - Summary of Earn-Out Liability (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Issuance of shares to settle earn-out obligation		$ (3,510)
Fair Value, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance at December 31, 2014	$ 0	3,510
Remeasurement of obligation	0	0
Issuance of shares to settle earn-out obligation		(3,510)
Balance at December 31, 2015	$ 0	$ 0