Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Held-to-maturity securities, fair value	$ 4,733	$ 4,617	$ 3,779
Unearned income on loans	776	805	923
Consolidated guaranteed funds VIEs, for accrued income and other assets	15	15	15
Consolidated education loan securitizations trust VIEs at fair value, Discontinued assets	1,912	1,912	1,912
Loan securitization trust VIEs	143	143	143
Aggregate amount of certificates of deposit	100000	100000	100000
Consolidated education loan securitization trust VIEs at fair value, Discontinued liabilities	$ 1,816	$ 1,816	$ 1,816
Preferred stock, par value	$ 1	$ 1	$ 1
Preferred stock, shares authorized	25,000,000	25,000,000	25,000,000
Common shares, par value	$ 1	$ 1	$ 1
Common shares, shares authorized	1,400,000,000	1,400,000,000	1,400,000,000
Common shares, shares issued	1,016,969,905	1,016,969,905	1,016,969,905
Treasury stock, shares	132,100,665	126,245,538	94,388,605
Series A Preferred Stock [Member]
Preferred stock, liquidation preference	$ 100	$ 100	$ 100
Preferred stock, shares authorized	7,475,000	7,475,000	7,475,000
Preferred stock, shares issued, Total	2,904,839	2,904,839	2,904,839
Preferred stock, dividend rate	7.75%	7.75%	7.75%