Offsetting of Assets and Liabilities (Offsetting of Derivative Liabilities and Securities Sold Under Agreements to Repurchase) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	$ 5,994.4	$ 1,566.5
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	5,268.1	1,283.5
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	726.3	283.0
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Net Amount	726.3	283.0
Total Derivatives Not Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	164.1	568.7
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0
NET AMOUNT	164.1	568.7
Offsetting Derivative Liabilities [Abstract]
GROSS RECOGNIZED LIABILITIES	6,158.5	2,135.2
Derivative Liabilities	890.4	851.7
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNT	890.4	851.7
Securities Sold under Agreements to Repurchase(2)
GROSS RECOGNIZED LIABILITIES	7,528.5	1,924.4
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	6,967.1	1,392.5
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	561.4	531.9
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	561.4	531.9
Other liabilities	3,500.0	3,300.0
Foreign Exchange Contracts | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	5,497.5	1,430.1
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	5,249.2	1,234.5
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	248.3	195.6
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Net Amount	248.3	195.6
Interest Rate Swap Contracts | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	453.7	98.7
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	18.9	48.1
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	434.8	50.6
Net Amount	434.8	50.6
Interest Rate Swap Contracts | Interest Rate Swaps Exchange Cleared
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	15.6	0.2
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	15.6	0.2
Net Amount	15.6	0.2
Other Financial Derivatives | Other Financial Derivatives
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	27.6	37.5
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	0.0	0.9
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	27.6	36.6
Net Amount	$ 27.6	$ 36.6