Income Taxes (Reconciliation of Statutory and Effective Tax Rates) (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%
Effective tax rate increase (decrease) - State taxes net of federal benefit	2.00%	2.30%	2.50%
Effective tax rate increase (decrease) - Tax-exempt interest	(1.70%)	(1.50%)	(1.70%)
Effective tax rate increase (decrease) - Life insurance	(1.60%)	(1.00%)	(1.00%)
Effective tax rate increase (decrease) - Tax credits	(6.00%)	(4.20%)	(4.00%)
Effective tax rate increase (decrease) - Federal deferred tax revaluation			(2.10%)
Effective tax rate increase (decrease) - Unrecognized tax benefits, Percent	(1.60%)	(0.10%)	1.30%
Effective tax rate increase (decrease) - Subsidiary Liquidation	(1.20%)
Effective tax rate increase (decrease) - Other	1.50%	(0.10%)	0.90%
Effective tax rate	12.40%	16.40%	16.90%