Reclassifications from Accumulated Other Comprehensive (Loss) Income - Schedule of Changes in AOCI by Component, Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	$ 1,485.9	$ 1,198.6	$ 1,104.9
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	(1.0)	0.0	0.0
Balances, end of period	1,520.1	1,485.9	1,198.6
Cash flow hedging items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	23.8	(2.3)	(21.8)
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	(1.0)
Other comprehensive (loss) income before reclassifications	(32.7)	26.9	5.8
Amounts reclassified from AOCI	(4.9)	(0.8)	13.7
Net current-period other comprehensive (loss) income	(38.6)	26.1
Balances, end of period	(14.8)	23.8	(2.3)
Pension and other postretirement benefit plan items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(220.4)	(299.0)
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	0.0
Other comprehensive (loss) income before reclassifications	(79.7)	69.7
Amounts reclassified from AOCI	6.8	8.9
Net current-period other comprehensive (loss) income	(72.9)	78.6
Balances, end of period	(293.3)	(220.4)	(299.0)
Unrealized losses on available-for-sale securities
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(0.3)	(0.3)
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	0.0
Other comprehensive (loss) income before reclassifications	0.3	0.0
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive (loss) income	0.3	0.0
Balances, end of period	0.0	(0.3)	(0.3)
Foreign currency items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(42.9)	(41.5)
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	0.0
Other comprehensive (loss) income before reclassifications	(0.8)	(1.4)
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive (loss) income	(0.8)	(1.4)
Balances, end of period	(43.7)	(42.9)	(41.5)
Total
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(239.8)	(343.1)
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	(1.0)
Other comprehensive (loss) income before reclassifications	(112.9)	95.2
Amounts reclassified from AOCI	1.9	8.1
Net current-period other comprehensive (loss) income	(112.0)	103.3
Balances, end of period	$ (351.8)	$ (239.8)	$ (343.1)

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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