Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Consolidated Balance Sheets
Trading account assets pledged as collateral	$ 25	$ 8
Fair value of securities held to maturity	$ 8,251	$ 6,439
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, share authorized	300,000,000	300,000,000
Common stock, share issued	136,330,830	136,330,830
Common stock, share outstanding	136,330,830	136,330,830