Consolidated Statements of Condition (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Pledged investment securities	$ 1,380	$ 434
Loans held-for-sale	$ 1,325	$ 1,115
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	515,000	515,000
Preferred stock, shares outstanding (in shares)	515,000	515,000
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	900,000,000	900,000,000
Common stock, shares issued (in shares)	744,520,822	705,429,386
Common stock, shares outstanding (in shares)	722,485,257	681,217,334
Treasury stock (in shares)	22,035,565	24,212,052
Net unrealized loss on securities available for sale, tax	$ 324	$ 240
Net unrealized loss on pension and post-retirement obligations, tax	17	18
Net unrealized (loss) gain on cash flow hedges, tax	$ (41)	$ (20)