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Basis of Presentation - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Mar. 31, 2018 | Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] |  |  |  |
Total costs and expenses | $ 176.5 | $ 189.2 | $ 468.7 | $ 540.5
Operating income (loss) | 17.0 | 7.7 | 109.0 | 30.4
Total other expense | $ (0.5) | 0.3 | $ (2.3) | (6.3)
Understated [Member] |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] |  |  |  |
Total costs and expenses |  | 5.2 |  | 2.0
Overstated [Member] |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] |  |  |  |
Operating income (loss) |  | 5.2 |  | 2.0
Total other expense |  | $ 5.2 |  | $ 2.0
Assurex [Member] |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] |  |  |  |
Non controlling interest ownership percentage by parent | 85.00% |  | 85.00% |
Centre For Addiction And Mental Health [Member] |  |  |  |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] |  |  |  |
Non controlling interest ownership percentage by noncontrolling owners | 15.00% |  | 15.00% |

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