Financial Instruments and Balance Sheet Classification (Parenthetical) (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2015 |
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| Investment Holdings [Line Items] | |||
| Obligations for which assets are held in trust | $ 137,100 | $ 138,800 | |
| Gain (loss) on marketable securities | $ 10,842 | $ (3,333) | $ 8,829 |
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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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- Definition This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the liabilities for deferred compensation arrangements classified as other. No definition available.
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