Intangible Assets, Net - Schedule of Activity in Intangible Assets, Net (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Intangible assets, net
Balance, beginning of period	$ 41,783	$ 44,633
Additions	2,400	1,075
Amortization	(2,511)	(2,998)
Balance, end of period	$ 41,672	$ 42,710