Loans - Loan Payment Modifications by Type of Modification (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Modified [Line Items]
Loans modified		$ 159
% of Total Loans		0.30%
Commercial loans
Financing Receivable, Modified [Line Items]
Loans modified	$ 65	$ 157
% of Total Loans	0.20%	0.40%
Commercial loans \| Real estate, including construction
Financing Receivable, Modified [Line Items]
Loans modified		$ 96
% of Total Loans		1.20%
Commercial loans \| Business and corporate banking
Financing Receivable, Modified [Line Items]
Loans modified	$ 65	$ 61
% of Total Loans	0.40%	0.40%
Consumer loans
Financing Receivable, Modified [Line Items]
Loans modified	$ 0	$ 2
% of Total Loans		0.00%
Consumer loans \| Residential mortgages
Financing Receivable, Modified [Line Items]
Loans modified		$ 1
% of Total Loans		0.00%
Consumer loans \| Credit cards
Financing Receivable, Modified [Line Items]
Loans modified		$ 1
% of Total Loans		0.50%
Interest Rate Reduction
Financing Receivable, Modified [Line Items]
Loans modified		$ 0
Interest Rate Reduction \| Commercial loans
Financing Receivable, Modified [Line Items]
Loans modified	0	0
Interest Rate Reduction \| Commercial loans \| Real estate, including construction
Financing Receivable, Modified [Line Items]
Loans modified		0
Interest Rate Reduction \| Commercial loans \| Business and corporate banking
Financing Receivable, Modified [Line Items]
Loans modified	0	0
Interest Rate Reduction \| Consumer loans
Financing Receivable, Modified [Line Items]
Loans modified		0
Interest Rate Reduction \| Consumer loans \| Residential mortgages
Financing Receivable, Modified [Line Items]
Loans modified		0
Interest Rate Reduction \| Consumer loans \| Credit cards
Financing Receivable, Modified [Line Items]
Loans modified		0
Principal Forgiveness
Financing Receivable, Modified [Line Items]
Loans modified		0
Principal Forgiveness \| Commercial loans
Financing Receivable, Modified [Line Items]
Loans modified	0	0
Principal Forgiveness \| Commercial loans \| Real estate, including construction
Financing Receivable, Modified [Line Items]
Loans modified		0
Principal Forgiveness \| Commercial loans \| Business and corporate banking
Financing Receivable, Modified [Line Items]
Loans modified	0	0
Principal Forgiveness \| Consumer loans
Financing Receivable, Modified [Line Items]
Loans modified		0
Principal Forgiveness \| Consumer loans \| Residential mortgages
Financing Receivable, Modified [Line Items]
Loans modified		0
Principal Forgiveness \| Consumer loans \| Credit cards
Financing Receivable, Modified [Line Items]
Loans modified		0
Term Extension / Significant Payment Deferral
Financing Receivable, Modified [Line Items]
Loans modified		146
Term Extension / Significant Payment Deferral \| Commercial loans
Financing Receivable, Modified [Line Items]
Loans modified	65	145
Term Extension / Significant Payment Deferral \| Commercial loans \| Real estate, including construction
Financing Receivable, Modified [Line Items]
Loans modified		96
Term Extension / Significant Payment Deferral \| Commercial loans \| Business and corporate banking
Financing Receivable, Modified [Line Items]
Loans modified	65	49
Term Extension / Significant Payment Deferral \| Consumer loans
Financing Receivable, Modified [Line Items]
Loans modified		1
Term Extension / Significant Payment Deferral \| Consumer loans \| Residential mortgages
Financing Receivable, Modified [Line Items]
Loans modified		0
Term Extension / Significant Payment Deferral \| Consumer loans \| Credit cards
Financing Receivable, Modified [Line Items]
Loans modified		1
Combination
Financing Receivable, Modified [Line Items]
Loans modified		13
Combination \| Commercial loans
Financing Receivable, Modified [Line Items]
Loans modified	0	12
Combination \| Commercial loans \| Real estate, including construction
Financing Receivable, Modified [Line Items]
Loans modified		0
Combination \| Commercial loans \| Business and corporate banking
Financing Receivable, Modified [Line Items]
Loans modified	$ 0	12
Combination \| Consumer loans
Financing Receivable, Modified [Line Items]
Loans modified		1
Combination \| Consumer loans \| Residential mortgages
Financing Receivable, Modified [Line Items]
Loans modified		1
Combination \| Consumer loans \| Credit cards
Financing Receivable, Modified [Line Items]
Loans modified		$ 0

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- Definition

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+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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