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Selected Financial Ratios and Other Data - Summary of Selected Financial Ratios and Other Data (Parenthetical) (Detail) $ / shares in Units, $ in Thousands | 3 Months Ended
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Mar. 31, 2018 USD ($) $ / shares
Investment Holdings [Line Items] |  |
Undistributed net investment income per share | $ / shares | $ 0.00 |
Undistributed net realized gains per share | $ / shares | $ 0.00 |
Servicing fee | $ | $ 1,290 |
Operating expenses | $ | $ 1,150 |
Total expense ratio | 10.02% | [1],[2]
Operating expense ratio | 5.87% | [1]
Excluding Impact of Medallion Servicing Corp. Amounts [Member] |  |
Investment Holdings [Line Items] |  |
Total expense ratio | 11.75% |
Operating expense ratio | 6.88% |
Net investment income ratio | 7.51% |
[1] | MSC has assumed certain of the Company’s servicing obligations, and as a result, servicing fee income of $1,290, and operating expenses of $1,150, which formerly were the Company’s, were now MSC’s for the three months ended March 31, 2018. Excluding the impact of the MSC amounts, the total expense ratio, operating expense ratio, and net investment income (loss) ratio would have been 11.75%, 6.88%, and 7.51% in the March 31, 2018 quarter.
[2] | Total expense ratio represents total expenses (interest expense, operating expenses, and income taxes) divided by average net assets.

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- Definition Income from mortgage banking activities (fees and commissions) and servicing real estate mortgages, credit cards, and other financial assets held by others net of any related impairment of capitalized service costs. Also includes any premiums received in lieu of regular servicing fees on such loans only as earned over the life of the loans. + References No definition available. + Details
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- Definition Percentage of investment income (loss) to average net assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 205 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=25866437&loc=d3e10328-115837 + Details
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