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Fair Value Of Financial Instruments (Difference Between Aggregate Fair Value And Aggregate Remaining Contractual Principal Balance Outstanding) (Detail) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
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Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items] |  |
Loans receivable, Contractual Outstanding Principal | $ 2,770 | $ 3,481
Variable interest entity notes, Contractual Outstanding Principal | 9,021 | 13,583
Loans receivable, Fair Value | 1,881 | 2,046
Variable interest entity notes, Fair Value | 3,659 | 4,754
Loans receivable, Difference | 889 | 1,435
Variable interest entity notes, Difference | 5,362 | 8,829
Residential Mortgage Loans [Member] |  |
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items] |  |
Loans receivable, Contractual Outstanding Principal | 2,307 | 2,769
Loans receivable, 90 days or more past due, Contractual Outstanding Principal | 244 | 259
Loans receivable, Fair Value | 1,735 | 1,895
Loans receivable, 90 days or more past due, Fair Value | 54 |
Loans receivable, Difference | 572 | 874
Loans receivable, 90 days or more past due, Difference | 190 | 259
Other Loans [Member] |  |
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items] |  |
Loans receivable, Contractual Outstanding Principal | 22 | 129
Loans receivable, 90 days or more past due, Contractual Outstanding Principal | 197 | 324
Loans receivable, Fair Value | 22 | 43
Loans receivable, 90 days or more past due, Fair Value | 70 | 108
Loans receivable, Difference |  | 86
Loans receivable, 90 days or more past due, Difference | $ 127 | $ 216

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- Definition This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 159 -Paragraph 18 -Subparagraph d(1) -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. + Details
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- Definition This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of long-term debt instruments that have contractual principal amounts and for which the fair value option has been elected. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 159 -Paragraph 18 -Subparagraph d(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. + Details
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- Definition This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 159 -Paragraph 18 -Subparagraph e(1) -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. + Details
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