CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)		Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Debt securities available for sale, amortized cost		$ 3,006,000,000	$ 3,275,000,000
Debt securities available for sale, allowance for credit losses		0
Debt securities held-to-maturity, fair value		3,072,000,000	3,305,000,000
Debt securities held to maturity, allowance for credit losses		50,000.00
Loans held for sale, fair value	[1]	138,000,000	41,000,000
Unearned income on loans		$ 111,000,000	$ 1,000,000
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Preferred stock, liquidation preference per share (in dollars per share)		$ 1,000	$ 1,000
Preferred stock, shares authorized		20,000,000	20,000,000
Preferred stock, shares issued		110,877	110,877
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized		500,000,000	500,000,000
Common stock, shares issued		328,004,096	327,242,364
Treasury stock, shares		4,791,698	2,227,804

[1] Amount represents loans for which we have elected the fair value option. See Note 19.