Assets Purchased under Resale Agreements and Sold under Repurchase Agreements (Repurchase Agreements) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amount of securities sold under repurchase agreements
Gross repurchase agreements	$ 300,000,000	$ 300,000,000
Weighted average interest rates	2.61%	3.25%	4.74%
Repurchase agreements’ extinguishment cost	$ 0	$ 8,740,000	$ 0
Extinguishment of repurchase agreements		$ 150,000,000.0