Consolidated Statements of Condition (Parenthetical) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Securities Available-for-sale, pledged	$ 1,016	$ 1,278
Preferred stock, par	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, Series A shares issued	515,000	515,000
Preferred stock, Series A shares outstanding	515,000	515,000
Common stock, par	$ 0.01	$ 0.01
Common stock, shares authorized	900,000,000	900,000,000
Common stock, shares issued	490,439,070	490,439,070
Common stock, shares outstanding	467,024,144	465,015,643
Treasury stock, shares	23,414,926	25,423,427
Net unrealized loss on securities available for sale, tax	$ 99	$ 17
Net unrealized loss on pension and post-retirement obligations, tax	12	12
Cash flow hedges tax component	$ (3)	$ 3