Offsetting of Assets and Liabilities - Offsetting of Derivative Liabilities and Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	$ 4,841.3	$ 2,806.3
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	4,199.6	2,205.4
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	641.7	600.9
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Derivative Liabilities	641.7	600.9
Total Derivatives Not Subject to a Master Netting Arrangement
Total Derivatives Not Subject to a Master Netting Arrangement	317.1	843.5
Total Derivatives
GROSS RECOGNIZED LIABILITIES	5,158.4	3,649.8
Derivative Liabilities	958.8	1,444.4
NET AMOUNT	958.8	1,444.4
Securities Sold under Agreements to Repurchase
GROSS RECOGNIZED LIABILITIES	65,374.8	62,860.2
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	64,912.8	62,075.5
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	462.0	784.7
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	462.0	784.7
NET AMOUNT	0.0	0.0
Foreign Exchange Contracts | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	4,392.7	2,411.7
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	4,197.3	2,175.7
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	195.4	236.0
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Derivative Liabilities	195.4	236.0
Interest Rate Swaps | Over the Counter Derivative
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	421.2	368.3
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	2.3	6.0
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	418.9	362.3
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Derivative Liabilities	418.9	362.3
Interest Rate Swaps | Interest Rate Swaps Exchange Cleared
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	0.2	0.9
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	0.0	0.0
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	0.2	0.9
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Derivative Liabilities	0.2	0.9
Other Financial Derivatives | Other Financial Derivatives
Total Derivatives Subject to a Master Netting Arrangement
GROSS RECOGNIZED LIABILITIES	27.2	25.4
GROSS AMOUNTS OFFSET IN THE BALANCE SHEET	0.0	23.7
NET AMOUNTS PRESENTED IN THE BALANCE SHEET	27.2	1.7
GROSS AMOUNTS NOT OFFSET IN THE BALANCE SHEET	0.0	0.0
Derivative Liabilities	$ 27.2	$ 1.7