CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 97,802	$ 97,569
Securities available for sale, allowance for credit loss	2	1
Loans held for sale	$ 908	$ 596
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	4,975,000	4,975,000
Preferred stock, shares outstanding	4,975,000	4,975,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	682,761,557	679,932,837
Common stock, shares outstanding	456,800,844	458,972,202
Treasury stock, par value (in dollars per share)	$ 0.01	$ 0.01
Treasury stock, shares	225,960,713	220,960,635