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Fair Value Measurements - Summary of Information about Described Model Inputs Used to Determine Fair Value of Each Class of Credit Derivative (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified | Sep. 30, 2012 | Dec. 31, 2011
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Schedule Of Information About Described Model Inputs Used To Determine Fair Value Of Each Class Of Credit Derivative [Line Items] |  |
Notional outstanding | $ 12,274,885 | $ 14,166,612
Weighted average life (WAL) in years | 8 years 1 month 6 days |
Weighted average quotes | 10.00% |
CVA percentage | 65.00% | 75.00%
Weighted average credit rating | A |
Fair value of derivative liabilities | (52,535) |
Other Contract [Member] |  |
Schedule Of Information About Described Model Inputs Used To Determine Fair Value Of Each Class Of Credit Derivative [Line Items] |  |
Notional outstanding |  | 1,838,269
Weighted average life (WAL) in years |  | 9 years
Weighted average quotes |  | 11.00%
CVA percentage |  | 75.00%
Weighted average credit rating |  | A+
Fair value of derivative liabilities |  | $ (49,807)

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- Definition Fair value input weighted average credit derivative quote as percentage of notional. + References No definition available. + Details
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- Definition Fair value input weighted average credit rating. + References No definition available. + Details
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- Definition Fair value input weighted average life. + References No definition available. + Details
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- Definition Credit valuation adjustment (CVA) as a percentage of the credit derivative liability calculated excluding the CVA. + References No definition available. + Details
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- Details
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- Definition Fair value of the gross liabilities less the gross assets of a derivative liability or group of derivative liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13495-108611 + Details
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- Definition Aggregate notional amount of credit risk derivatives. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Notional Amount -URI http://asc.fasb.org/extlink&oid=6519104 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959 + Details
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