Income Taxes (Reconciliation of Income Tax Provision) (Details 2)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the income tax provision
Tax at U.S. statutory rate (as a percent)	21.00%	21.00%	21.00%
Changes in taxes resulting from:
Low income housing tax credit (as a percent)	(4.30%)	(3.60%)	(3.20%)
State taxes, net of federal benefit (as a percent)	2.10%	2.40%	1.50%
Dividend received deduction (as a percent)	(2.10%)	(1.80%)	(1.60%)
Incentive compensation (as a percent)	(1.40%)	0.00%	0.00%
Foreign tax credits, net of addback (as a percent)	0.00%	(2.20%)	(1.10%)
Other, net (as a percent)	0.90%	(0.60%)	(1.10%)
Income tax provision (as a percent)	16.20%	15.20%	15.50%