Fair Values of Assets and Liabilities - Losses Realized on Assets Measured on Non-Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Impaired loans	$ (6,991)	$ (382)	$ (14,576)	$ (843)
Other real estate owned	(245)	(1,126)	(258)	(1,154)
Total losses	$ (7,236)	$ (1,508)	$ (14,834)	$ (1,997)