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Investment, Carried at Cost - Additional Information (Detail) | 12 Months Ended
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Dec. 31, 2016 USD ($) shares
Schedule of Cost-method Investments [Line Items] |
Cost method investments | $ 20,000,000
Advisor Engine Inc. [Member] |
Schedule of Cost-method Investments [Line Items] |
Date of agreement | Nov. 18, 2016
Cost method investments | $ 20,000,000
Ownership interest percentage | 36.00%
Impairment losses | $ 0
Advisor Engine Inc. [Member] | Series A Preferred [Member] |
Schedule of Cost-method Investments [Line Items] |
Number of shares purchased | shares | 11,811,856
Advisor Engine Inc. [Member] | Series A Preferred [Member] |
Schedule of Cost-method Investments [Line Items] |
Non-cumulative dividend | 6.00%

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- Definition This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 325 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596 + Details
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