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, 2017	Jun. 30, 2016
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	$ 1,104.9	$ 1,325.9
Balances, end of period	1,198.6	1,104.9
Cash flow hedging items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(21.8)	(28.5)
Other comprehensive income (loss) before reclassifications	5.7	(20.8)
Amounts reclassified from AOCI	13.8	27.5
Net current-period other comprehensive (loss) income	19.5	6.7
Balances, end of period	(2.3)	(21.8)
Pension and other postretirement benefit plan items
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(344.3)	(256.8)
Other comprehensive income (loss) before reclassifications	22.4	(102.5)
Amounts reclassified from AOCI	22.9	15.0
Net current-period other comprehensive (loss) income	45.3	(87.5)
Balances, end of period	(299.0)	(344.3)
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	(43.5)	(42.6)
Other comprehensive income (loss) before reclassifications	2.0	(0.9)
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive (loss) income	2.0	(0.9)
Balances, end of period	(41.5)	(43.5)
Total
Changes in the balance of Accumulated Other Comprehensive Income
Balances, beginning of period	(409.9)	(328.2)
Other comprehensive income (loss) before reclassifications	30.1	(124.2)
Amounts reclassified from AOCI	36.7	42.5
Net current-period other comprehensive (loss) income	66.8	(81.7)
Balances, end of period	$ (343.1)	$ (409.9)

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84158357&loc=d3e1436-108581

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Section 45
-Paragraph 14A
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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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