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Worker's Compensation Claims - Summary of Risk Retained by Insured Program after Considering Loss Portfolio Transfers and Current Insurance Arrangements (Details) | 12 Months Ended
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Sep. 30, 2021
2014 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No
2015 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No
2016 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No
2017 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No
2018 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No
2019 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | Yes
2020 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | Yes
2021 - Through June 30 [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | Yes
2021 - July 1 and After [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Claims risk retained | No

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