Net interest revenue (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Interest revenue
Deposits with the Federal Reserve and other central banks	$ (7)	$ 80	$ 113	$ 73		$ 252
Deposits with banks	40	58	64	98		127
Federal funds sold and securities purchased under resale agreements	61	396	568	457		1,042
Margin loans	40	87	119	127		254
Non-margin loans	230	309	365	539		720
Securities:
Taxable	556	594	687	1,150		1,393
Exempt from federal income taxes	6	6	10	12		22
Total securities	562	600	697	1,162		1,415
Trading securities	17	40	39	57		75
Total interest revenue	943	1,570	1,965	2,513		3,885
Interest expense
Deposits	(17)	240	432	223		823
Federal funds purchased and securities sold under repurchase agreements	1	275	372	276		703
Trading liabilities	2	7	11	9		18
Other borrowed funds	7	4	20	11		44
Commercial paper	1	6	18	7		26
Customer payables	(1)	30	69	29		139
Long-term debt	170	194	241	364		489
Total interest expense	163	756	1,163	919		2,242
Net interest revenue	780	814	802	1,594		1,643
Provision for credit losses	143	169	(8)	312	[1]	(1)	[1]
Net interest revenue after provision for credit losses	$ 637	$ 645	$ 810	$ 1,282		$ 1,644

[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.