Loans and asset quality - Information about Past Due Loans (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 05, 2022	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Total past due loans		$ 69,347	$ 67,787
Total past due
Financing Receivable, Past Due [Line Items]
Total past due loans		213	94
Total past due | Capital call financing
Financing Receivable, Past Due [Line Items]
Total past due loans		120	0
Total past due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total past due loans		39	3
Total past due | Wealth management loans
Financing Receivable, Past Due [Line Items]
Total past due loans		27	33
Total past due | Financial institutions
Financing Receivable, Past Due [Line Items]
Total past due loans		19	31
Total past due | Other residential mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		8	3
Total past due | Wealth management mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		0	24
30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total past due loans		82	93
30 to 59 Days Past Due | Subsequent Event
Financing Receivable, Past Due [Line Items]
Proceeds from collection of past due loans (over)	$ 26
30 to 59 Days Past Due | Capital call financing
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total past due loans		39	3
30 to 59 Days Past Due | Wealth management loans
Financing Receivable, Past Due [Line Items]
Total past due loans		26	33
30 to 59 Days Past Due | Financial institutions
Financing Receivable, Past Due [Line Items]
Total past due loans		9	31
30 to 59 Days Past Due | Other residential mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		8	2
30 to 59 Days Past Due | Wealth management mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		0	24
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total past due loans		131	1
60 to 89 Days Past Due | Subsequent Event
Financing Receivable, Past Due [Line Items]
Proceeds from collection of past due loans (over)	$ 121
60 to 89 Days Past Due | Capital call financing
Financing Receivable, Past Due [Line Items]
Total past due loans		120	0
60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
60 to 89 Days Past Due | Wealth management loans
Financing Receivable, Past Due [Line Items]
Total past due loans		1	0
60 to 89 Days Past Due | Financial institutions
Financing Receivable, Past Due [Line Items]
Total past due loans		10	0
60 to 89 Days Past Due | Other residential mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		0	1
60 to 89 Days Past Due | Wealth management mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Capital call financing
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Wealth management loans
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Financial institutions
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Other residential mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		0	0
Equal to Greater than 90 Days Past Due | Wealth management mortgages
Financing Receivable, Past Due [Line Items]
Total past due loans		$ 0	$ 0