Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Other Expenses [Abstract]
Professional services	$ 105		$ 99	$ 326	$ 315
Sales advertising and public relations	45		38	104	91
Securities processing	16		10	43	35
Regulatory fees and assessments	12		18	162	62
Bank operations	11		9	33	33
Donations	1		13	27	26
Other	105		98	318	279
Total other expenses	$ 295		$ 285	$ 1,013	$ 841
FDIC special assessment expense		$ 130