Borrowed Funds - Breakdown of borrowed funds (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
FHLB advances	$ 20,350	$ 20,325
Total wholesale borrowings	20,350	20,325
Junior subordinated debentures	576	575
Subordinated notes	434	432
Total borrowed funds	$ 21,360	$ 21,332

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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