Derivative Financial Instruments (Location and Amount of Fair Value And Cash Flow Hedge Derivative Gains And Losses Recorded In Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income	$ 1,935.0	$ 799.3	$ 5,125.4	$ 1,707.6
Interest Expense	1,478.8	286.3	3,626.5	354.9
Other Operating Income	68.2	57.3	170.2	144.0
INTEREST INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized on fair value hedges	11.1	(4.0)	34.7	(13.3)
Gains (Losses) on cash flow hedges recognized on	14.6	0.0	15.8	0.6
INTEREST EXPENSE
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized on fair value hedges	(24.9)	(6.9)	(65.9)	18.0
Gains (Losses) on cash flow hedges recognized on	0.0	0.0	0.0	0.0
OTHER OPERATING INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized on fair value hedges	0.0	0.0	0.0	0.0
Gains (Losses) on cash flow hedges recognized on	0.3	(0.6)	1.9	(4.4)
Interest Rate Contracts | INTEREST INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	14.1	32.3	0.6	90.0
Recognized on hedged items	(14.1)	(32.3)	(0.6)	(90.0)
Amounts related to interest settlements on derivatives	11.1	(4.0)	34.7	(13.3)
Interest Rate Contracts | INTEREST EXPENSE
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(41.8)	(119.9)	(42.5)	(373.6)
Recognized on hedged items	41.8	119.9	42.5	373.6
Amounts related to interest settlements on derivatives	(24.9)	(6.9)	(65.9)	18.0
Interest Rate Contracts | OTHER OPERATING INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	0.0	0.0	0.0	0.0
Recognized on hedged items	0.0	0.0	0.0	0.0
Amounts related to interest settlements on derivatives	0.0	0.0	0.0	0.0
Foreign Exchange Contracts | INTEREST INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on cash flow hedges recognized on	14.6	0.0	15.8	0.6
Foreign Exchange Contracts | INTEREST EXPENSE
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on cash flow hedges recognized on	0.0	0.0	0.0	0.0
Foreign Exchange Contracts | OTHER OPERATING INCOME
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on cash flow hedges recognized on	$ 0.3	$ (0.6)	$ 1.9	$ (4.4)