Basis of presentation (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020		Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Total fee revenue	$ 3,265	$ 3,224	$ 3,074	[1]	$ 9,746	$ 9,401	[1]
Investment and other income	127	89	61	[1]	225	240	[1]
Foreign exchange revenue	185	184	149	[1]	600	587	[1]
Other revenue	129	91	70	[1]	229	267	[1]
Net securities gains	$ 2	$ 2	9		$ 4	27
Investment Services
Income Statement [Abstract]
Foreign exchange revenue						518
Other revenue						458
Other
Income Statement [Abstract]
Total fee revenue						23
Other revenue						65
Previously Reported
Income Statement [Abstract]
Foreign exchange and other trading revenue			137			622
Total fee revenue			3,108			9,598
Investment and other income			46			162
Income from consolidated investment management funds			$ 27			43
Previously Reported | Investment Services
Income Statement [Abstract]
Foreign exchange and other trading revenue						585
Other revenue						391
Previously Reported | Other
Income Statement [Abstract]
Total fee revenue						61
Net securities gains						$ 27

[1] In the first quarter of 2021, we reclassified certain items within total revenue on the consolidated income statement and reclassified prior periods to be comparable with the current period presentation. See Note 1 of the Notes to Consolidated Financial Statements for additional information.