Loans - Summary of Receivables which were Modified and as Result Became Classified as TDR Loans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 468	$ 65
Commercial loans
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	442	26
Commercial loans | Business and corporate banking
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	439	11
Commercial loans | Global banking
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	3	15
Consumer loans
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	26	39
Consumer loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	20	36
Consumer loans | Home equity mortgages
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	2	1
Consumer loans | Credit cards
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 4	$ 2