Income Taxes - Schedule of Statutory to Effective Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory tax rate	35.00%	35.00%	35.00%
Low income housing tax credits	(4.40%)	(5.80%)	(6.80%)
Tax-exempt interest	(4.10%)	(4.60%)	(4.50%)
Bank owned life insurance	(0.80%)	(0.80%)	(1.00%)
Other	1.00%	(0.60%)	(0.40%)
Effective Tax Rate	26.70%	23.20%	22.30%