PARENT COMPANY FINANCIAL STATEMENTS - Schedule of Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 2,777	$ 11,466	$ 1,098
Adjustments to reconcile net income to cash provided by operating activities:
Deferred tax expense (benefit)	6	(165)	206
Fair value adjustment on marketable equity securities, net	(13)	11	3
Stock based compensation expense	0	5	19
Realized (gain) loss on sale of investment securities, net	0	26	0
Net change in other assets	(495)	206	484
Net change in other liabilities	(34)	(379)	260
Other operating activities	1	(21)	(36)
Net cash provided by operating activities	2,988	2,660	2,791
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease in interest-earning deposits at banks	12,245	5,416	6,965
Purchase of marketable equity securities	(6)	0	0
Proceeds from sales of investments in marketable equity securities	15	0	0
Other investing activities	(473)	208	(108)
Net cash (used in) provided by investing activities	(10,155)	2,429	75
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of Class A common stock	(1,648)	0	(1,240)
Cash dividends paid	(158)	(117)	(83)
Other financing activities	(14)	(7)	(24)
Net cash provided by (used in) financing activities	7,073	(4,699)	(2,686)
Net change in cash and due from banks	(94)	390	180
Cash and due from banks at beginning of period	908	518	338
Cash and due from banks at end of period	814	908	518
CASH PAYMENTS (REFUNDS) FOR:
Income taxes	763	514	(551)
Parent
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	2,777	11,466	1,098
Adjustments to reconcile net income to cash provided by operating activities:
(Undistributed) distributed net income of subsidiaries	(586)	(11,155)	221
Deferred tax expense (benefit)	2	(5)	48
Net amortization of premiums and discounts	0	0	1
Fair value adjustment on marketable equity securities, net	(13)	11	6
Stock based compensation expense	0	5	19
Realized (gain) loss on sale of investment securities, net	(6)	0	0
Net change in other assets	(15)	(17)	(3)
Net change in other liabilities	(5)	3	(2)
Other operating activities	3	0	0
Net cash provided by operating activities	2,157	308	1,388
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease in interest-earning deposits at banks	4	(2)	3
Purchase of marketable equity securities	(6)	0	0
Proceeds from sales of investments in marketable equity securities	15	0	0
Note receivable from banking subsidiary	(200)	0	0
Net cash paid in acquisition	0	0	(51)
Other investing activities	(23)	0	0
Net cash (used in) provided by investing activities	(210)	(2)	(48)
CASH FLOWS FROM FINANCING ACTIVITIES
Repayment of other borrowings	0	0	(68)
Repayment of subordinated debt	(17)	(87)	0
(Repayment) proceeds for borrowings due to banking subsidiary	(1)	(15)	20
Repurchase of Class A common stock	(1,648)	0	(1,240)
Cash dividends paid	(158)	(117)	(83)
Other financing activities	(13)	(6)	(24)
Net cash provided by (used in) financing activities	(1,837)	(225)	(1,395)
Net change in cash and due from banks	110	81	(55)
Cash and due from banks at beginning of period	200	119	174
Cash and due from banks at end of period	310	200	119
CASH PAYMENTS (REFUNDS) FOR:
Interest	15	23	18
Income taxes	$ (1)	$ 470	$ (536)