XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.21.2

Investments (Tables) | 3 Months Ended
--- | ---
Jul. 31, 2021
Investments |
Schedule of investments | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | July 31, | ​ | April 30, | ​
​ |  | 2021 |  | 2021 |
Short-term investments: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Available-for-sale securities: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Municipal securities | ​ | ​ | 12,264 | ​ | ​ | 22,245 | ​
U.S. government securities | ​ | ​ | — | ​ | ​ | 4,009 | ​
Corporate bonds | ​ | ​ | 5,689 | ​ | ​ | 5,717 | ​
Total short-term investments | ​ | $ | 17,953 | ​ | $ | 31,971 | ​
Long-term investments: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Available-for-sale securities: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Municipal securities | ​ | ​ | 987 | ​ | ​ | 988 | ​
U.S. government securities | ​ | ​ | — | ​ | ​ | 4,000 | ​
Total long-term available-for-sale investments | ​ |  | 987 | ​ |  | 4,988 | ​
Equity method investments | ​ | ​ | ​ | ​ | ​ | ​ | ​
Investment in limited partnership fund | ​ |  | 9,178 | ​ |  | 7,168 | ​
Total equity method investments | ​ |  | 9,178 | ​ |  | 7,168 | ​
Total long-term investments | ​ | $ | 10,165 | ​ | $ | 12,156 | ​
Schedule of activity related to available-for-sale investments recorded in short-term and long-term investments | The following table is a summary of the activity related to the available-for-sale investments recorded in short-term and long-term investments as of July 31, 2021 and April 30, 2021, respectively (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | July 31, 2021 | ​ | ​
​ |  | ​ | ​ |  | Gross |  | Gross |  | ​ | ​ |  |
​ | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | Fair | ​ | ​
​ | ​ | Cost | ​ | Gains | ​ | Losses | ​ | Value | ​ | ​
Municipal securities | ​ | $ | 13,249 | ​ | $ | 3 | ​ | $ | (1) | ​ | $ | 13,251 | ​ | ​
Corporate bonds | ​ | ​ | 5,689 | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 5,689 | ​ | ​
Total available-for-sale investments | ​ | $ | 18,938 | ​ | $ | 3 | ​ | $ | (1) | ​ | $ | 18,940 | ​ | ​
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | April 30, 2021 | ​
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | Fair |
​ | ​ | Cost |  | Gains | ​ | Losses |  | Value |
Municipal securities |  | $ | 23,227 | ​ | $ | 8 | ​ | $ | (2) | ​ | $ | 23,233 | ​
U.S. government securities | ​ |  | 8,008 | ​ | ​ | 1 | ​ | ​ | — | ​ | ​ | 8,009 | ​
Corporate bonds | ​ |  | 5,718 | ​ | ​ | — | ​ | ​ | (1) | ​ | ​ | 5,717 | ​
Total available-for-sale investments |  | $ | 36,953 |  | $ | 9 | ​ | $ | (3) |  | $ | 36,959 | ​
Schedule of amortized cost and fair value of the available-for-sale debt securities by contractual maturity | The amortized cost and fair value of the available-for-sale debt securities by contractual maturity at July 31, 2021 were as follows (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | Cost |  | Fair Value |
Due within one year | ​ | $ | 17,953 | ​ | $ | 17,953 | ​
Due after one year through five years | ​ |  | 985 | ​ |  | 987 | ​
Total | ​ | $ | 18,938 | ​ | $ | 18,940 | ​

X
- Definition Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -URI http://asc.fasb.org/topic&trid=2196928 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117539-209714 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the summary of investment holdings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B) -URI http://asc.fasb.org/extlink&oid=120401592&loc=d3e611197-123010 + Details
Name: | us-gaap_SummaryInvestmentHoldingsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration