Goodwill and Other Intangible Assets - Schedule of Net Carrying Amount of Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 935	$ 1,089	$ 1,089
Acquisitions			34
Amortization	(57)	(54)	(223)
Foreign currency translation	(6)		35
Ending balance	872		935
Investment Servicing
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	916	1,063	1,063
Acquisitions			34
Amortization	(55)		(216)
Foreign currency translation	(6)		35
Ending balance	855		916
Investment Management
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	19	$ 26	26
Acquisitions			0
Amortization	(2)		(7)
Foreign currency translation	0		0
Ending balance	$ 17		$ 19