Other Comprehensive Income - Summary of Other Comprehensive Income and Tax Impact (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract]
Unrealized gain (loss) on available-for-sale securities, income tax expense (benefit)	$ 27	$ (24)	$ 331	$ (145)
Unrealized gain (loss) on interest rate swaps, income tax expense (benefit)	$ (61)	$ 38	$ (419)	$ 230