Income Taxes Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory Federal Tax Rate	21.00%	21.00%	21.00%
Tax-Exempt Income	(2.10%)	(2.70%)	(3.10%)
Nondeductible Interest Expense	0.10%	0.20%	0.10%
State Taxes, Net of Federal Income Tax Benefit	2.60%	2.30%	2.40%
Tax benefit from stock based compensation	(0.10%)	(0.30%)	(0.40%)
Other Items, Net	(0.20%)	(0.10%)	(0.10%)
Effective Tax Rate	21.30%	20.40%	19.90%