Accounts Receivable - Summary of Activity in Allowances for Doubtful Accounts, Returns and Discounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Balance at Beginning of Period	$ 7,057	$ 8,214	$ 9,595
Charges to Revenue	1,826	2,181	537
Charges (Credits) to Expense	208	(238)	423
Additions to (Deductions from) Reserves	(4,751)	(3,100)	(2,341)
Balance at End of Period	$ 4,340	$ 7,057	$ 8,214