Other Comprehensive Income - Summary of Other Comprehensive Income and Tax Impact (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract]
Net unrealized (loss) gain on available-for-sale securities, net of income taxes	$ (65)	$ 11	$ (391)	$ 162
Net unrealized gain on interest rate swaps, net of income taxes	123	11	749	82
Foreign currency translation	(3)	(6)	(15)	(11)
Total other comprehensive income	$ 55	$ 16	$ 343	$ 233