Net interest revenue (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Interest revenue
Deposits with the Federal Reserve and other central banks	$ (10)	$ (7)	$ 102	$ 63		$ 354
Deposits with banks	20	40	73	118		200
Federal funds sold and securities purchased under resale agreements	48	61	660	505		1,702
Margin loans	41	40	104	168		358
Non-margin loans	199	230	287	738		1,007
Securities:
Taxable	499	556	669	1,649		2,062
Exempt from federal income taxes	7	6	7	19		29
Total securities	506	562	676	1,668		2,091
Trading securities	16	17	40	73		115
Total interest revenue	820	943	1,942	3,333		5,827
Interest expense
Deposits	(29)	(17)	437	194		1,260
Federal funds purchased and securities sold under repurchase agreements	6	1	443	282		1,146
Trading liabilities	2	2	8	11		26
Other borrowed funds	3	7	10	14		54
Commercial paper	0	1	22	7		48
Customer payables	0	(1)	59	29		198
Long-term debt	135	170	233	499		722
Total interest expense	117	163	1,212	1,036		3,454
Net interest revenue	703	780	730	2,297		2,373
Provision for credit losses	9	143	(16)	321	[1]	(17)	[1]
Net interest revenue after provision for credit losses	$ 694	$ 637	746	$ 1,976		2,390
Operating lease, impairment loss			$ 70			$ 70

[1] In the first quarter of 2020, we adopted new accounting guidance included in ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments, on a prospective basis. See Note 2 of the Notes to Consolidated Financial Statements for additional information.