Parent Company Financial Statements - Condensed Statement of Income (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income
Noninterest income	$ 2,427	$ 2,528	$ 2,357
Expense
Interest on short-term borrowings	242	292	19
Interest expense	637	400	111
Other	5,359	5,379	5,050
Income tax credits	(722)	(878)	(620)
Net income	$ 2,588	$ 2,741	$ 1,992
Net income per common share
Earnings per share, basic (in USD per share)	$ 14.71	$ 15.85	$ 11.59
Earnings per share, diluted (in USD per share)	$ 14.64	$ 15.79	$ 11.53
Parent Company
Income
Dividends from consolidated subsidiaries	$ 1,306	$ 2,041	$ 2,508
Interest income	77	6	1
Noninterest income	4	0	(8)
Total revenue	1,435	2,067	2,531
Expense
Interest expense	274	182	63
Other	62	40	50
Total expense	336	222	113
Income before income taxes and equity in undistributed income of subsidiaries	1,099	1,845	2,418
Income tax credits	51	49	22
Income before equity in undistributed income of subsidiaries	1,150	1,894	2,440
Net income of subsidiaries	2,744	2,888	2,060
Less: dividends received	(1,306)	(2,041)	(2,508)
Equity in undistributed income of subsidiaries	1,438	847	(448)
Net income	$ 2,588	$ 2,741	$ 1,992
Net income per common share
Earnings per share, basic (in USD per share)	$ 14.71	$ 15.85	$ 11.59
Earnings per share, diluted (in USD per share)	$ 14.64	$ 15.79	$ 11.53
Parent Company | Bayview Lending Group, LLC
Income
Income from BLG	$ 48	$ 20	$ 30