Expenses - Restructuring Reserve (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022
Restructuring Reserve [Roll Forward]
Beginning balance	$ 56	$ 74	$ 186	$ 196	$ 74
Accruals				2	45
Payments and Other Adjustments	(11)	(18)	(34)	(11)
Ending balance		56	152	186
State Street Beacon
Restructuring Reserve [Roll Forward]
Accruals				(1)
Employee Related Costs
Restructuring Reserve [Roll Forward]
Beginning balance	51	68	180	190	68
Accruals				0	40
Payments and Other Adjustments	(11)	(17)	(34)	(9)
Ending balance		51	146	180
Employee Related Costs | State Street Beacon
Restructuring Reserve [Roll Forward]
Accruals				(1)
Real Estate Actions
Restructuring Reserve [Roll Forward]
Beginning balance	5	6	6	6	6
Accruals				2	5
Payments and Other Adjustments	0	(1)	0	(2)
Ending balance		5	6	6
Real Estate Actions | State Street Beacon
Restructuring Reserve [Roll Forward]
Accruals				0
Asset and Other Write-offs
Restructuring Reserve [Roll Forward]
Beginning balance	0	0	0	0	0
Accruals				0	$ 0
Payments and Other Adjustments	$ 0	0	0	0
Ending balance		$ 0	$ 0	0
Asset and Other Write-offs | State Street Beacon
Restructuring Reserve [Roll Forward]
Accruals				$ 0