Variable Interest Entities (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Affordable housing tax credits and other tax benefits	$ 28,500,000	$ 26,100,000	$ 85,100,000	$ 74,500,000
Investment company, voluntary fee waived	2,200,000	$ 2,600,000	6,500,000	$ 61,900,000
Contractual obligation to provide financial support	0		0
Fair value investments, seed capital investments					$ 19,900,000
Unfunded commitments	$ 0		$ 0		$ 0