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Annual coverage limit provided by the insurance arrangement for malpractice claims.

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Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Sep. 30, 2018 Facility	Jun. 30, 2019 USD ($)
Loss Contingencies [Line Items]
Maximum professional liability aggregate policy limit			$ 75,000,000.0
West Virginia [Member]
Loss Contingencies [Line Items]
Number of comprehensive treatment centers operate \| Facility		7
Amount paid to government	$ 17,000,000.0
Maximum [Member]
Loss Contingencies [Line Items]
Maximum self insured professional liability limit per claim			3,000,000.0
Minimum [Member]
Loss Contingencies [Line Items]
Maximum professional liability retention limit			$ 3,000,000.0