Income Taxes - Schedule of Components of Consolidated Statements of Income and Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax expense	$ 212	$ 247	$ 274
Net unrealized gains (losses) on pension and other postretirement plans	(1)	(5)	2
Net unrealized gains (losses) on securities available for sale	44	(302)	(46)
Net unrealized gains (losses) on cash flow hedges	15	(42)	(3)
Total	$ 270	$ (102)	$ 227