Summary of Significant Accounting Policies - Summary of Changes in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Beginning balance – allowance for doubtful accounts	$ 4,180	$ 4,540	$ 3,002
Provision for doubtful accounts	2,318	2,437	2,797
Write-offs	(1,739)	(2,797)	(1,259)
Ending balance – allowance for doubtful accounts	$ 4,759	$ 4,180	$ 4,540