CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Pension and post-retirement benefits, tax (expense) benefit	$ (8.4)	$ (55.3)	$ (13.2)
Net gain (loss) on derivative instruments, tax (expense) benefit	$ 0.5	$ (5.7)	$ (1.2)

Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e640-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669646-108580

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
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-URI https://asc.fasb.org/extlink&oid=126929396&loc=SL4569616-111683

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