Pledged Assets, Collateral and Restricted Assets (Accepted Collateral) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Jun. 30, 2023
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total Collateral Accepted	$ 12,574.4	$ 35,864.7
Fair value of securities received as collateral that have been resold or repledged		34,600.0
Securities received as collateral, amount repledged and sold	11,500.0
Reverse repurchase agreements
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral that may be repledged or sold	12,119.4	35,560.8
Reverse repurchase agreements	450.0	300.0
DERIVATIVE CONTRACTS
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral that may be repledged or sold	$ 5.0	$ 3.9