Business Combination - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	9 Months Ended	12 Months Ended
	Jun. 17, 2015	Jan. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Common stock, par value				$ 0.001	$ 0.001
Business combination, additional earnout shares added to escrow fund				11,059
Business combination, escrow fund date	2018-01
Goodwill				$ 2,863	$ 2,683
IDchecker [Member]
Business Acquisition [Line Items]
Acquisition date	Jun. 17, 2015
Total consideration paid	$ 5,900
Payments to acquire businesses, gross	5,600
Business combination consideration transfer, promissory notes	300
Common stock issued during acquisition, value	$ 2,700
Common stock, par value	$ 0.001
Business combination, paid earnout shares issued		137,306	137,306	55,297
Cash payment to escrow fund related to business acquisition	$ 1,800
Business combination, percentage of closing shares in escrow fund	20.00%
Business combination, deposited earnout shares in escrow fund		27,461
Goodwill	$ 2,900				$ 2,683
IDchecker [Member] | Closing Shares [Member]
Business Acquisition [Line Items]
Common stock issued during acquisition, share	712,790