Reclassifications from Accumulated Other Comprehensive (Loss) Income (AOCI) - Schedule of changes in AOCI by component, net of tax (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances at the beginning of the period	$ 1,407.5	$ 1,577.0	$ 1,445.7	$ 1,520.1
Other comprehensive (loss) income before reclassifications	15.7	(9.4)	31.8	15.8
Amounts reclassified from AOCI	1.6	0.7	3.1	(0.3)
Other comprehensive income (loss), net of tax	17.3	(8.7)	34.9	15.5
Balances at the end of the period	1,332.9	1,603.4	1,332.9	1,603.4
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances at the beginning of the period	(380.4)	(327.6)	(398.0)	(351.8)
Balances at the end of the period	(363.1)	(336.3)	(363.1)	(336.3)
Cash flow hedging items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances at the beginning of the period	(2.8)	11.9	(11.1)	(14.8)
Other comprehensive (loss) income before reclassifications	6.9	(16.8)	17.3	13.9
Amounts reclassified from AOCI	(2.0)	(2.3)	(4.1)	(6.3)
Other comprehensive income (loss), net of tax	4.9	(19.1)	13.2	7.6
Balances at the end of the period	2.1	(7.2)	2.1	(7.2)
Pension and other postretirement benefit plan items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances at the beginning of the period	(330.7)	(290.3)	(334.3)	(293.3)
Other comprehensive (loss) income before reclassifications	0.0	0.0	0.0	0.0
Amounts reclassified from AOCI	3.6	3.0	7.2	6.0
Other comprehensive income (loss), net of tax	3.6	3.0	7.2	6.0
Balances at the end of the period	(327.1)	(287.3)	(327.1)	(287.3)
Foreign currency items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances at the beginning of the period	(46.9)	(49.2)	(52.6)	(43.7)
Other comprehensive (loss) income before reclassifications	8.8	7.4	14.5	1.9
Amounts reclassified from AOCI	0.0	0.0	0.0	0.0
Other comprehensive income (loss), net of tax	8.8	7.4	14.5	1.9
Balances at the end of the period	$ (38.1)	$ (41.8)	$ (38.1)	$ (41.8)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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