Securities (Details Textual) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012 Securities Bonds	Jun. 30, 2012 Securities Bonds	Jun. 30, 2011	Dec. 31, 2011 Bonds Securities
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	$ 58,804,000,000	$ 58,804,000,000		$ 51,791,000,000
Foreign bonds issued by the governments of Greece, Ireland, Italy, Portugal or Spain	0	0		0
Securities at amortized cost issued or guaranteed, held to maturity	2,100,000,000	2,100,000,000		2,300,000,000
Securities (Additional Textual) [Abstract]
Assets Backed Securities in Available for Sale Portfolio	35	35		45
Assets Backed Securities Wrapped by Insurance Company	9	9		9
Value of Asset Backed Securities Backed by Insurance Company	336,000,000	336,000,000		349,000,000
Fair value of Assets Backed Securities	655,000,000	655,000,000		818,000,000
Percentage of debt securities issued out of available for sale of securities and held to maturity	84.00%	84.00%		86.00%
Temporary impairment losses recognized credit loss	0	0
Non-credit component unrealized loss amounts recognized	0	0
Unrealized Losses on Assets backed securities, Gross	104,000,000	104,000,000		121,000,000
Fair Value of Financial Guarantee from Insurance Company for the purpose of evaluating other then temporary Impairment	108,000,000	108,000,000		114,000,000
Security wrapped by below investment grade monoline insurance was deemed to be other-than-temporarily impaired	0	0		1
Other Than Temporary Impaired				1,000,000
Debt securities were determined to have either initial other-than-temporary impairment or changes to previous estimates relating to the credit component	0		0
Impairment losses other-than-temporary recognized related to credit loss	0		0
Remaining non-credit component unrealized loss recognized	0		0
US Treasury Securities [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	27,886,000,000	27,886,000,000		18,199,000,000
Mortgage-backed securities, US Government sponsored enterprises [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	37,000,000	37,000,000		40,000,000
Mortgage-backed securities, US Government sponsored enterprises [Member] | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	14,000,000	14,000,000		13,000,000
Mortgage-backed securities, US Government sponsored enterprises [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	23,000,000	23,000,000		27,000,000
Mortgage-backed securities, US Government agency issued or guaranteed [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	14,774,000,000	14,774,000,000		15,357,000,000
Mortgage-backed securities, US Government agency issued or guaranteed [Member] | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Securities (Textual) [Abstract]
Securities at amortized cost issued or guaranteed, held to maturity	736,000,000	736,000,000		830,000,000
Mortgage-backed securities, US Government agency issued or guaranteed [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Securities (Textual) [Abstract]
Securities at amortized cost issued or guaranteed, held to maturity	554,000,000	554,000,000		591,000,000
Corporate and other domestic [Member] | FDIC [Member]
Securities (Textual) [Abstract]
Other domestic debt securities at amortized cost	16,000,000	16,000,000		516,000,000
Corporate and Other Domestic Debt Securities [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	40,000,000	40,000,000		541,000,000
Foreign debt securities [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	6,869,000,000	6,869,000,000		6,640,000,000
Foreign debt securities [Member] | FDIC [Member]
Securities (Textual) [Abstract]
Foreign debt securities fully backed by foreign governments	2,400,000,000	2,400,000,000		2,700,000,000
Equity Securities [Member]
Securities (Textual) [Abstract]
Securities at amortized cost of issued or guaranteed	171,000,000	171,000,000		130,000,000
Equity Securities [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Securities (Textual) [Abstract]
Preferred equity securities at amortized cost	2,000,000	2,000,000		2,000,000
Preferred equity securities reflect cumulative other-than-temporary impairment charges	173,000,000	173,000,000		173,000,000
Federal Home Loan Bank [Member]
Securities (Textual) [Abstract]
Investments in stock were included in other assets	143,000,000	143,000,000		133,000,000
Federal Reserve Bank [Member]
Securities (Textual) [Abstract]
Investments in stock were included in other assets	$ 483,000,000	$ 483,000,000		$ 483,000,000