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Securities Owned and Securities Sold, but not yet Purchased (and Fair Value Measurement) - Ranges and Weighted Averages of Significant Unobservable Inputs Used to Determine Enterprise Value of Tradeworx (Detail) - Preferred Stock [Member] - Level 3 [Member] | Apr. 30, 2017
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Minimum [Member] | Income Approach Valuation Technique [Member] |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |
Weighted average cost of capital ("WACC") | 11.50%
Maximum [Member] | Income Approach Valuation Technique [Member] |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |
Weighted average cost of capital ("WACC") | 14.50%
Weighted Average [Member] | Income Approach Valuation Technique [Member] |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |
Weighted average cost of capital ("WACC") | 12.60%
Weighted Average [Member] | Market Approach Valuation Technique [Member] |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |
Revenue multiple | 0.9

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- Definition Market valuation of entity divided by revenue, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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