Allowance for Credit Losses - Changes in Allowance for Credit Losses (Parenthetical) (Detail) - USD ($) $ in Millions		12 Months Ended
	Apr. 01, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for credit losses		$ 645	$ 517	$ (75)
Charge-offs		$ (570)	$ (303)	$ (338)
Non PCD Acquired Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for credit losses	$ 242
Charge-offs	(242)
PCD Acquired Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Charge-offs	$ (33)