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Significant Accounting Policies (Narrative) (Detail) | 12 Months Ended
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Dec. 31, 2012
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items] |
Controlling financial interest in or exert significant influence over an entity | 20.00%
Percentage of qualified financial guarantee contracts | 91.00%

X
- Definition Controlling Financial Interest Evidenced By Voting Interest Greater Than Certain Percentage + References No definition available. + Details
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Balance Type: | na
Period Type: | duration

X
- Definition Percentage Of Qualified Financial Guarantee Contracts + References No definition available. + Details
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Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Details
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Balance Type: | na
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