PARENT COMPANY FINANCIALS - Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
ASSETS:
Cash and due from banks	$ 1,489	$ 1,155
Other assets	13,089	8,746
TOTAL ASSETS	226,733	188,409
LIABILITIES:
Long-term borrowed funds	15,887	6,932
Other liabilities	4,520	3,425
TOTAL LIABILITIES	203,043	164,989
Total stockholders’ equity	23,690	23,420	$ 22,673	$ 22,201
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	226,733	188,409
Parent company
ASSETS:
Cash and due from banks	1,821	2,266
Other assets	182	140
TOTAL ASSETS	27,267	26,771
LIABILITIES:
Long-term borrowed funds	3,336
Other liabilities	241	252
TOTAL LIABILITIES	3,577	3,351
Total stockholders’ equity	23,690	23,420
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	27,267	26,771
Bank subsidiaries | Parent company
ASSETS:
Loans and advances	1,153	1,148
Investments in subsidiaries	23,674	22,742
Nonbank subsidiaries | Parent company
ASSETS:
Loans and advances	135	150
Investments in subsidiaries	302	325
Unaffiliated companies | Parent company
LIABILITIES:
Long-term borrowed funds	$ 3,336	$ 3,099