COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Administration and Other Fiduciary Fees (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Commissions and fees
Total administration and other fiduciary fees	$ 1,045	$ 1,037
Custody fees
Commissions and fees
Total administration and other fiduciary fees	479	514
Fiduciary fees
Commissions and fees
Total administration and other fiduciary fees	434	392
Guarantee fees
Commissions and fees
Total administration and other fiduciary fees	132	131
Administration and other fiduciary fees
Commissions and fees
Total administration and other fiduciary fees	1,045	1,037
Revenue not accounted for under ASC 606, revenue from contracts with customers	$ 132	$ 131