GUARANTEES AND COMMITMENTS (Details 2) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Credit Commitments.
Credit Commitments	$ 928,651,000,000	$ 911,802,000,000
Commercial and similar letters of credit
Credit Commitments.
Credit Commitments	8,617,000,000	8,910,000,000
One-to four-family residential mortgages
Credit Commitments.
Credit Commitments	3,138,000,000	3,504,000,000
Revolving open-end loans secured by one- to four-family residential properties
Credit Commitments.
Credit Commitments	19,148,000,000	19,326,000,000
Commercial real estate, construction and land development.
Credit Commitments.
Credit Commitments	2,035,000,000	1,968,000,000
Credit card lines
Credit Commitments.
Credit Commitments	658,196,000,000	653,985,000,000
Commercial and other consumer loan commitments
Credit Commitments.
Credit Commitments	237,517,000,000	224,109,000,000
Commercial and other consumer loan commitments, original maturity of less than one year	68,000,000,000	65,000,000,000
U.S.
Credit Commitments.
Credit Commitments	684,812,000,000
U.S. | Commercial and similar letters of credit
Credit Commitments.
Credit Commitments	1,554,000,000
U.S. | One-to four-family residential mortgages
Credit Commitments.
Credit Commitments	2,596,000,000
U.S. | Revolving open-end loans secured by one- to four-family residential properties
Credit Commitments.
Credit Commitments	16,162,000,000
U.S. | Commercial real estate, construction and land development.
Credit Commitments.
Credit Commitments	1,613,000,000
U.S. | Credit card lines
Credit Commitments.
Credit Commitments	520,981,000,000
U.S. | Commercial and other consumer loan commitments
Credit Commitments.
Credit Commitments	141,906,000,000
Outside of U.S.
Credit Commitments.
Credit Commitments	243,839,000,000
Outside of U.S. | Commercial and similar letters of credit
Credit Commitments.
Credit Commitments	7,063,000,000
Outside of U.S. | One-to four-family residential mortgages
Credit Commitments.
Credit Commitments	542,000,000
Outside of U.S. | Revolving open-end loans secured by one- to four-family residential properties
Credit Commitments.
Credit Commitments	2,986,000,000
Outside of U.S. | Commercial real estate, construction and land development.
Credit Commitments.
Credit Commitments	422,000,000
Outside of U.S. | Credit card lines
Credit Commitments.
Credit Commitments	137,215,000,000
Outside of U.S. | Commercial and other consumer loan commitments
Credit Commitments.
Credit Commitments	$ 95,611,000,000