Inventories - Narrative (Details) $ in Millions	12 Months Ended
Jun. 30, 2020 USD ($) facility	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Inventory [Line Items]
Inventory LIFO reserve	$ 134.5	$ 178.4
Current cost of LIFO inventory	722.5	793.0
Decrease in cost of sales	1.8	(0.0)	$ 0.6
Inventory adjustment	$ 29.3	$ 0.0	$ 0.0
Facility Closing
Inventory [Line Items]
Number of power production facilities closed \| facility	2

Restructuring And Related Cost, Number Of Power Production Facilities Closed

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- Definition

The effect of liquidating LIFO (last in first out) inventory layers on income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section S99
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-Subparagraph (SAB Topic 11.F)
-URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100079-122729

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- Definition

Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=116847112&loc=d3e4542-108314

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- Definition

The amount of LIFO (last in first out) inventory present at the reporting date when inventory is also valued using different valuation methods.

+ References

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