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Guarantees, Commitments and Contingencies - Additional Information (Detail) - USD ($) | 3 Months Ended |
--- | --- | ---
Sep. 30, 2015 | Sep. 30, 2014 | Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract] |  |  |
Credit losses associated with derivative contracts | $ 0 | $ 0 |
Outstanding commitments to purchase securities | 3,500,000 |  | $ 0
Outstanding commitments to sell securities | $ 0 |  | $ 0

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- Definition Securities committed to sell amount. + References No definition available. + Details
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