CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Securities held to maturity, at fair value	$ 303	$ 10
Loans held-for-sale, at fair value	301	405
Loans and leases, at fair value	$ 0	$ 16
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	26,750	26,250
Common stock, par value (in dollars per share)	$ 0.625	$ 0.625
Common stock, shares authorized (in shares)	700,000,000	700,000,000
Common stock, shares issued (in shares)	541,859,599	555,030,652