The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 7
-Footnote 2
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 15C
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 15D
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Securities Available for Sale, Residential Mortgage-Backed Securities, Credit Loss Component (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Credit Impairment Losses On Residential Mortgage Backed Securities [Abstract]
Securities available for sale	$ 189	$ 106	$ 269	$ 212
Non-agency residential MBS non-investment grade [Abstract]
Expected remaining life of loan losses From	0.00		0.00
Expected remaining life of loan losses To	0.40		0.40
Credit impairment distribution [Abstract]
0 - 10% range			45.00%	53.00%
10 - 20% range			16.00%	14.00%
20 - 30% range			30.00%	29.00%
Greater than 30%			9.00%	4.00%
Weighted average			0.11	0.09
Current subordination levels [Abstract]
Current subordination levels From	0.00		0.00
Current subordination levels To	0.13		0.13
Current subordination levels Weighted average			0.05	0.07
Prepayment speed (annual CPR)
Prepayment speed From	0.05		0.05
Prepayment speed To	0.14		0.15
Prepayment speed Weighted average			0.11	0.09
Residential [Member] \| Investment Grade [Member]
Credit Impairment Losses On Residential Mortgage Backed Securities [Abstract]
Securities available for sale			5
Investment Grade [Member]
Credit Impairment Losses On Residential Mortgage Backed Securities [Abstract]
Securities available for sale	0	0		0
Non-investment Grade [Member]
Credit Impairment Losses On Residential Mortgage Backed Securities [Abstract]
Securities available for sale	144	37	201	76
Residential [Member]
Credit Impairment Losses On Residential Mortgage Backed Securities [Abstract]
Securities available for sale	$ 144	$ 37	$ 206	$ 76
Non-agency residential MBS non-investment grade [Abstract]
Expected remaining life of loan losses From		0.01		0.01
Expected remaining life of loan losses To		0.40		0.40
Credit impairment distribution [Abstract]
0 - 10% range	40.00%	54.00%
10 - 20% range	13.00%	8.00%
20 - 30% range	35.00%	34.00%
Greater than 30%	12.00%	4.00%
Weighted average	0.12	0.08
Current subordination levels [Abstract]
Current subordination levels From		0		0
Current subordination levels To		0.25		0.25
Current subordination levels Weighted average	0.04	0.07
Prepayment speed (annual CPR)
Prepayment speed From		0.03		0.03
Prepayment speed To		0.17		0.17
Prepayment speed Weighted average	0.11	0.09