Securities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 15,490	$ 21,535
Gross Unrealized Gains	522	485
Gross Unrealized Losses		87
Fair Value	16,012	21,933
HELD-TO-MATURITY SECURITIES
Held-to-maturity securities	2,109	17
Held-to-maturity Securities, Unrecognized Holding Gains	24
Fair Value	2,133	17
US Treasury and Government [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost		8
Fair Value		8
US States and Political Subdivisions Debt Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	60	170
Gross Unrealized Gains	3	2
Fair Value	63	172
HELD-TO-MATURITY SECURITIES
Held-to-maturity securities	0	1
Fair Value	0	1
Collateralized Mortgage Backed Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	14,707	20,344
Gross Unrealized Gains	455	408
Gross Unrealized Losses		87
Fair Value	15,162	20,665
HELD-TO-MATURITY SECURITIES
Held-to-maturity securities	2,091	0
Held-to-maturity Securities, Unrecognized Holding Gains	24
Fair Value	2,115	0
Mortgage Backed Securities, Other [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	715	998
Gross Unrealized Gains	63	71
Fair Value	778	1,069
Other Debt Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	8	15
Gross Unrealized Gains	1	4
Fair Value	9	19
HELD-TO-MATURITY SECURITIES
Held-to-maturity securities	18	16
Held-to-maturity Securities, Unrecognized Holding Gains	0
Fair Value	$ 18	$ 16

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

+ References+ Details

This item represents the gross unrealized losses for securities which are categorized neither as held-to-maturity nor trading securities. Such gross unrealized losses are the excess of the carrying value of the Available-for-sale Securities over their fair value as of the reporting date. Such gross unrealized losses are included in other comprehensive income in the statement of shareholders' equity, unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

+ References+ Details