XML 41 R28.htm IDEA: XBRL DOCUMENT
v3.21.2

Nature of Operations and Summary of Significant Accounting Policies - Company's Assets Measured at Fair Value (Detail) - USD ($) | Sep. 30, 2021 | Sep. 30, 2020
--- | --- | ---
Investment Holdings [Line Items] |  |
Total | $ 94,976,000 | $ 89,498,000
Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 70,123,000 | 61,621,000
Level 2 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 24,853,000 | 27,877,000
Equities [Member] |  |
Investment Holdings [Line Items] |  |
Total | 14,734,000 | 11,949,000
Equities [Member] | Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 14,734,000 | 11,949,000
Mutual Funds [Member] |  |
Investment Holdings [Line Items] |  |
Total | 10,357,000 | 9,595,000
Mutual Funds [Member] | Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 10,357,000 | 9,595,000
Exchange Traded Funds [Member] |  |
Investment Holdings [Line Items] |  |
Total | 9,458,000 | 10,344,000
Exchange Traded Funds [Member] | Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 9,458,000 | 10,344,000
Corporate Bonds [Member] |  |
Investment Holdings [Line Items] |  |
Total | 24,853,000 | 27,877,000
Corporate Bonds [Member] | Level 2 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 24,853,000 | 27,877,000
Government Securities [Member] |  |
Investment Holdings [Line Items] |  |
Total | 30,999,000 | 16,147,000
Government Securities [Member] | Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | 30,999,000 | 16,147,000
Cash and Money Funds [Member] |  |
Investment Holdings [Line Items] |  |
Total | 4,575,000 | 13,586,000
Cash and Money Funds [Member] | Level 1 [Member] |  |
Investment Holdings [Line Items] |  |
Total | $ 4,575,000 | $ 13,586,000

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

X
- Definition Amount of investment in marketable security, classified as current. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_MarketableSecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MutualFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_ExchangeTradedFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasuryAndGovernmentShorttermDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |