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Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Other Intangible Assets (Details) € in Millions, $ in Millions	3 Months Ended					6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Finite-lived Intangible Assets [Roll Forward]
Beginning balance				$ 1,827		$ 1,816	$ 1,827	$ 1,827
Acquisitions						0		264
Amortization	$ (60)		$ (63)			(121)	(121)	(245)
Foreign currency translation						(41)		(30)
Ending balance	1,654					1,654		1,816
Investment Servicing
Finite-lived Intangible Assets [Roll Forward]
Beginning balance				1,733		1,746	1,733	1,733
Acquisitions						0		264
Amortization						(110)		(221)
Foreign currency translation						(41)		(30)
Ending balance	1,595					1,595		1,746
Investment Servicing \| Fideuram Bank Luxembour
Finite-lived Intangible Assets [Roll Forward]
Payment for acquisition				258	€ 220
Investment Servicing \| Mercatus, Inc
Finite-lived Intangible Assets [Roll Forward]
Payment for acquisition		$ 88
Investment Management
Finite-lived Intangible Assets [Roll Forward]
Beginning balance				$ 94		70	$ 94	94
Acquisitions						0		0
Amortization						(11)		(24)
Foreign currency translation						0		0
Ending balance	$ 59					$ 59		$ 70