Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held to maturity, Fair Value		$ 3,305	$ 3,155
Loans held for sale	[1]	41	14
Unearned income on loans		$ 1	$ 3
Preferred stock, par value (USD per Share)		$ 0.01	$ 0.01
Preferred stock, liquidation preference per share (USD per Share)		$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)		20,000,000	20,000,000
Preferred stock, shares issued (in shares)		110,877	110,877
Common stock, par value (USD per Share)		$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		500,000,000	500,000,000
Common stock, shares issued (in shares)		327,242,364	326,120,832
Treasury stock, shares (in shares)		2,227,804	1,806,303

[1] Amount represents loans for which we have elected the fair value option. See Note 24.