Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%
State income taxes, net of federal tax benefit	7.90%	7.70%	7.90%
Tax-exempt interest on municipal obligations	(0.50%)	(0.90%)	(0.70%)
Tax-exempt life insurance related income	(0.50%)	(0.80%)	(0.60%)
Low income housing tax credits	(2.60%)	(4.80%)	(2.30%)
Low income housing tax credit amortization	2.20%	4.10%	2.10%
Equity compensation	(0.10%)	0.40%	(0.40%)
Non-deductible merger expenses	0.10%	0.00%	0.00%
Other	0.60%	(0.90%)	0.40%
Effective Tax Rate	28.10%	25.80%	27.40%