Income Taxes - Statutory to Effective Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Statutory tax rate	21.00%	21.00%	21.00%
Low income housing tax credits	(11.10%)	(3.30%)	(2.50%)
Tax-exempt interest	(11.90%)	(2.10%)	(2.10%)
Bank owned life insurance	(1.80%)	(0.40%)	(0.40%)
Gain on sale of a majority interest of insurance business	0.00%	0.00%	0.70%
Merger related expenses	0.00%	0.30%	0.00%
Other	3.80%	0.80%	0.30%
Impact of the Tax Act	0.00%	0.00%	(2.50%)
Effective Tax Rate	0.00%	16.30%	14.50%