Nature of Business and Summary of Significant Accounting Policies - Activity in Allowance for Doubtful Accounts Receivable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Balance, beginning of period	$ (5,045)	$ (4,806)	$ (4,459)
Provision (increase) decrease	(1,595)	(2,425)	(1,049)
Amounts written off, net of recoveries	2,551	2,088	1,053
Foreign currency translation adjustments and other	216	98	(351)
Balance, end of period	$ (3,873)	$ (5,045)	$ (4,806)