Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Interest bearing deposits in banks	$ 1,479,000,000	$ 2,764,000,000
Trading account assets pledged as collateral	34,000,000	14,000,000
Securities available for sale pledged as collateral	4,800,000,000
Fair value of securities held to maturity	2,536,000,000	1,429,000,000
Other assets	3,383,000,000	3,365,000,000
Long-term debt	6,444,000,000	6,684,000,000
Other liabilities	1,712,000,000	2,019,000,000
Preferred stock, shares authorized		5,000,000,000,000
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	136,330,830
Common stock, shares outstanding	136,330,830	136,330,830
Consolidated VIEs [Member]
Interest bearing deposits in banks	8,000,000	8,000,000
Other assets	331,000,000	286,000,000
Long-term debt	8,000,000	8,000,000
Other liabilities	$ 1,000,000	$ 1,000,000