Offsetting of Assets and Liabilities (Offsetting of Derivative Liabilities and Securities Sold Under Agreements to Repurchase) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	$ 2,884.3	$ 1,371.1
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	2,752.4	1,175.7
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	131.9	195.4
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNT	131.9	195.4
Total Derivatives Not Subject to a Master Netting Arrangement
Total Derivatives Not Subject to a Master Netting Arrangement	437.0	1,038.5
Offsetting Derivative Liabilities [Abstract]
GROSS RECOGNIZED LIABILITIES	3,321.3	2,409.6
Derivative Liabilities	568.9	1,233.9
NET AMOUNT	568.9	1,233.9
Securities Sold under Agreements to Repurchase
GROSS RECOGNIZED LIABILITIES	92,684.6	90,307.8
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	92,509.0	90,015.6
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	175.6	292.2
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	175.6	292.2
NET AMOUNT	0.0	0.0
Foreign Exchange Contracts | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	2,859.2	1,334.8
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	2,729.3	1,139.4
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	129.9	195.4
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNT	129.9	195.4
Interest Rate Swap Contracts | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	2.0	5.0
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	0.0	5.0
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	2.0	0.0
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNT	2.0	0.0
Other Financial Derivatives | Other Financial Derivatives
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	23.1	31.3
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	23.1	31.3
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	0.0	0.0
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNT	$ 0.0	$ 0.0