Investments in Marketable Securities - Additional Information (Detail) - USD ($) |
12 Months Ended | |
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Dec. 31, 2016 |
Dec. 31, 2015 |
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| Schedule of Available-for-sale Securities [Line Items] | ||
| Gross realized loss | $ 166,000 | $ 3,000 |
| Sale of Available-For-Sale, Marketable Security that No Longer Met Investment Policy [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Gross realized loss | $ 152,000 | |
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- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Details
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