CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
ASSETS:
Securities held-to-maturity, fair value	$ 5,058	$ 5,297
STOCKHOLDERS’ EQUITY:
Preferred stock, par value (in dollars per share)	$ 25.00	$ 25.00
Preferred stock, authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, issued (in shares)	564,630,542	563,117,415
Common stock, outstanding (in shares)	511,954,871	527,774,428
Treasury stock (in shares)	52,675,671	35,342,987
Series A Preferred Stock
STOCKHOLDERS’ EQUITY:
Preferred stock, par value (in dollars per share)	$ 25.00	$ 25.00
Preferred stock, authorized (in shares)	250,000	250,000
Preferred stock, issued (in shares)	250,000	250,000
Preferred stock, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Available-for-sale Securities
ASSETS:
Securities, pledged to creditors	$ 256	$ 4,283
Held-to-maturity Securities
ASSETS:
Securities, pledged to creditors	$ 0	$ 135