Income Taxes - Schedule of Reconciliation of Uncertain Tax Position (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Balance as of January 1	$ 1,024	$ 1,166
Additions for tax positions taken in prior years		50
Additions for tax positions of acquired company		1,139
Statute expirations	(576)
Reductions for settlements on tax positions of acquired company		(165)
Reductions of tax positions taken in prior years	(47)
Reductions for settlements on tax positions of prior years		(1,166)
Balance as of December 31	$ 401	$ 1,024