Schedule II-Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ (7,009)	$ (2,798)	$ (597)
Charged to Costs and Expenses	(4,059)	(4,211)	(2,201)
Charged to Other Accounts	0	0	0
Balance at End of Year	(11,068)	(7,009)	(2,798)
Valuation Allowance of Deferred Tax Assets
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	(5,839)	(2,798)	(597)
Charged to Costs and Expenses	(3,713)	(3,041)	(2,201)
Charged to Other Accounts	0	0	0
Balance at End of Year	(9,552)	(5,839)	$ (2,798)
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	(1,170)
Charged to Costs and Expenses	(346)	(1,170)
Charged to Other Accounts	0	0
Balance at End of Year	$ (1,516)	$ (1,170)