Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Interest bearing deposits in banks	$ 2,764	$ 217
Trading account assets pledged as collateral	14	43
Securities available for sale pledged as collateral	0	10
Fair value of securities held to maturity	1,429	1,560
Other asset	3,365	3,499
Long-term debt	6,684	5,598
Other liabilities	2,019	1,024
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares, issued	136,330,830	136,330,829
Common stock, shares outstanding	136,330,830	136,330,829
Variable Interest Entity, Not Primary Beneficiary
Interest bearing deposits in banks	8	11
Other asset	286	283
Long-term debt	8	8
Other liabilities	$ 1	$ 2