PARENT COMPANY FINANCIALS - Condensed Balance Sheets (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
ASSETS:
Cash and due from banks	[1]	$ 1,794	$ 1,489
Other assets	[1]	13,359	13,089
TOTAL ASSETS		221,964	226,733
LIABILITIES:
Long-term borrowed funds	[1]	13,467	15,887
Other liabilities	[1]	4,746	4,520
TOTAL LIABILITIES		197,622	203,043
Total stockholders’ equity		24,342	23,690	$ 23,420	$ 22,673
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY		221,964	226,733
Parent company
ASSETS:
Cash and due from banks		2,864	1,821
Other assets		194	182
TOTAL ASSETS		27,944	27,267
LIABILITIES:
Long-term borrowed funds		3,344
Other liabilities		258	241
TOTAL LIABILITIES		3,602	3,577
Total stockholders’ equity		24,342	23,690
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY		27,944	27,267
Bank subsidiaries | Parent company
ASSETS:
Loans and advances		1,152	1,153
Investments in subsidiaries		23,289	23,674
Nonbank subsidiaries | Parent company
ASSETS:
Loans and advances		154	135
Investments in subsidiaries		291	302
Unaffiliated companies | Parent company
LIABILITIES:
Long-term borrowed funds		$ 3,344	$ 3,336

[1] Includes amounts in consolidated VIEs. See Note 11 for additional information.