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Summary of Significant Accounting Policies - Concentration of Credit Risk (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Jun. 30, 2020
Medicare | Revenues | Customer Concentration Risk |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk percentage | 60.00% | 53.00% |
Medicare | Accounts Receivable | Credit Concentration Risk |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk percentage | 31.00% |  | 28.00%
Previously Reported |  |  |
Concentration Risk [Line Items] |  |  |
Cost of goods and services |  | $ 12.4 |

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