Income Taxes - Valuation Allowances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	$ 7,832	$ 2,006	$ 1,833
Charged to costs and expenses	5,347	6,625	0
(Deductions)/Other	0	(799)	173
Balance at December 31	$ 13,179	$ 7,832	$ 2,006