Derivatives and Hedging Activities - Schedule of Cumulative Basis Adjustments on Fair Value Hedges (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Fair Value	$ 37,460	$ 37,185
Long-term debt | Interest rate
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	10,165	9,919
Hedge accounting basis adjustment	(572)	(437)
Long-term debt | Interest rate | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Hedge accounting basis adjustment	(5)	(5)
Securities Available for Sale | Interest rate
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	10,654	8,655
Hedge accounting basis adjustment	29	(152)
Fair Value	12,500	12,800
Hedged layer amount	7,200	7,200
Hedged asset portfolio layer method cumulative basis adjustments	$ 19	$ (147)