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Shareholders' Equity - Additional Information (Detail) | 12 Months Ended
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Sep. 30, 2019
Common Stock [Member] |
Class of Stock [Line Items] |
Right of holders to elect company's board of directors | 25.00%
Class B Stock [Member] |
Class of Stock [Line Items] |
Right of holders to elect company's board of directors | 75.00%

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- Definition Right of holders to elect company's board of directors. + References No definition available. + Details
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Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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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. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
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Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |