Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Tax at statutory rate	21.00%	21.00%	21.00%
Nontaxable interest and dividends	(0.30%)	(0.50%)	(0.50%)
Tax credits	(1.80%)	(3.80%)	(3.60%)
State taxes	1.30%	1.40%	1.30%
Other	0.70%	0.80%	0.10%
Effective income tax rate reconciliation	20.90%	18.90%	18.30%