Debt (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Line of credit maximum capacity	$ 6,000.0	$ 4,000.0
Fees to maintain credit lines	21.8	14.2
Interest paid	$ 8,000.0	8,200.0	$ 6,400.0
Minimum
Debt Instrument [Line Items]
Common equity tier one ratio	0.045
Maximum
Debt Instrument [Line Items]
Common equity tier one ratio	0.065
Short-term Debt
Debt Instrument [Line Items]
Fees to maintain credit lines	$ 13.1	11.9
Lending Trust
Debt Instrument [Line Items]
Line of credit maximum capacity	2,000.0
Subsidiaries
Debt Instrument [Line Items]
Line of credit maximum capacity	123.0	191.0
Amount drawn from committed lines	12.0	$ 16.0
Charge Trust
Debt Instrument [Line Items]
Line of credit maximum capacity	$ 3,000.0
Specified date face amount of eligible notes issued	Jul. 17, 2028