Variable interest entities - Assets and Liabilities of VIEs (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Trading assets	$ 10,759	$ 16,577
Other assets	1,268	1,187
Other liabilities	31	496
Nonredeemable noncontrolling interests	7	196
VME classification of carrying amount, assets	105	187
VME classification of carrying amount, liabilities	1	2
Noncontrolling interest in VME	7	43
Investment Management funds | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Trading assets	191	443
Other assets	5	19
Total assets	196	462
Other liabilities	1	3
Total liabilities	1	3
Nonredeemable noncontrolling interests	$ 7	$ 196