Off-Balance-Sheet Risk and Concentration of Credit Risk (Detail) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Off-Balance-Sheet Risk and Concentration of Credit Risk [Abstract] | ||
| Receivables from clearing broker | $ 48,543 | $ 41,492 |
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- Definition Off-Balance-Sheet Risk and Concentration of Credit Risk [Abstract] No definition available.
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- Definition Amount of right to receive cash and securities on deposit with clearing organizations. Clearing organizations perform post trade processing and trade comparisons among numerous broker-dealers and act as settlement agents between buying and selling broker-dealers. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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