Income Taxes Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory tax rate	21.00%	21.00%	35.00%
Tax credit investments	(4.60%)	(6.10%)	(7.80%)
Tax-exempt income	(3.90%)	(4.10%)	(6.60%)
Bank owned life insurance	(0.40%)	(0.40%)	(0.40%)
State income taxes, net of federal benefit	0.20%	2.00%	(0.50%)
Change in valuation allowance	1.80%	(0.10%)	1.20%
Re-measurement of net deferred tax asset due to the Tax Act	0.00%	(0.30%)	6.70%
Executive compensation	0.00%	0.10%	0.10%
Other, net	0.20%	(1.60%)	(1.00%)
Effective income tax rate	14.30%	10.50%	26.70%