Loans Receivable and Allowance for Credit Losses - Allowance for Credit Losses Narrative (Details) $ in Millions	Dec. 31, 2024 USD ($) quarter	Dec. 31, 2023 USD ($)	Sep. 30, 2023 qtr	Jun. 30, 2023 qtr
Financing Receivable, Allowance for Credit Losses
Life time loss rate, period span | quarter	8
Financing receivable and off balance sheet credit loss allowance	$ 742	$ 706
Commercial lending
Financing Receivable, Allowance for Credit Losses
Collateral dependent loans	45	30
Consumer Lending
Financing Receivable, Allowance for Credit Losses
Collateral dependent loans	$ 23	$ 12
C&I
Financing Receivable, Allowance for Credit Losses
Life time loss rate, period span | qtr			8	11