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, 2018	Jun. 30, 2017
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	$ 1,198.6	$ 1,104.9
Balances, end of period	1,485.9	1,198.6
Cash flow hedging items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(2.3)	(21.8)
Other comprehensive income (loss) before reclassifications	26.9	5.7
Amounts reclassified from AOCI	(0.8)	13.8
Net current-period other comprehensive (loss) income	26.1	19.5
Balances, end of period	23.8	(2.3)
Pension and other postretirement benefit plan items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(299.0)	(344.3)
Other comprehensive income (loss) before reclassifications	69.7	22.4
Amounts reclassified from AOCI	8.9	22.9
Net current-period other comprehensive (loss) income	78.6	45.3
Balances, end of period	(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)
Other comprehensive income (loss) before reclassifications	0.0	0.0
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive (loss) income	0.0	0.0
Balances, end of period	(0.3)	(0.3)
Foreign currency items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(41.5)	(43.5)
Other comprehensive income (loss) before reclassifications	(1.4)	2.0
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive (loss) income	(1.4)	2.0
Balances, end of period	(42.9)	(41.5)
Total
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(343.1)	(409.9)
Other comprehensive income (loss) before reclassifications	95.2	30.1
Amounts reclassified from AOCI	8.1	36.7
Net current-period other comprehensive (loss) income	103.3	66.8
Balances, end of period	$ (239.8)	$ (343.1)

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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