Guarantee Arrangements and Pledged Assets and Repurchase Agreements - Offsetting of Resale and Repurchase Agreements and Securities Borrowing and Lending Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Securities purchased under agreements to resell, Gross Amounts Recognized	$ 19,382	$ 27,795
Securities purchased under agreements to resell, Gross Amounts Offset in the Balance Sheet	5,504	4,710
Securities purchased under agreements to resell, Net amounts Presented in the Balance Sheet	13,878	23,085
Securities purchased under agreements to resell, Gross Amounts Not Offset in the Balance Sheet, Financial Instruments	13,677	23,082
Securities purchased under agreements to resell, Gross Amounts Not Offset in the Balance Sheet, Cash Collateral Receive / Pledged	7	0
Securities purchased under agreements to resell, Net amount	194	3
Securities sold under repurchase agreements, Gross Amounts Recognized	5,771	4,710
Securities sold under repurchase agreements, Gross Amounts Offset in the Balance Sheet	5,504	4,710
Securities sold under repurchase agreements, Net Amounts Presented in the Balance Sheet	267	0
Securities sold under repurchase agreements, Gross Amounts Not Offset in the Balance sheet, Financial Instruments	266	0
Securities sold under repurchase agreements, Gross Amounts Not Offset in the Balance Sheet, Cash Collateral Received / Pledged	0	0
Securities sold under repurchase agreements, Net amount	$ 1	$ 0