Borrowings - Short-term Borrowings (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Short-term Debt	$ 13,736	$ 5,292
Federal Funds Purchased
Short-term Debt [Line Items]
Short-term Debt	2,942	0
Securities Sold under Agreements to Repurchase
Short-term Debt [Line Items]
Short-term Debt	1,938	2,435
FHLB Advances
Short-term Debt [Line Items]
Short-term Debt	6,000	0
Dealer Collateral
Short-term Debt [Line Items]
Short-term Debt	420	318
Master Notes
Short-term Debt [Line Items]
Short-term Debt	620	808
Securities sold short
Short-term Debt [Line Items]
Short-term Debt	$ 1,816	$ 1,731

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant