Inventories - Inventory Components (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Mar. 31, 2021	Mar. 31, 2021	Jun. 30, 2020
Inventory Disclosure [Abstract]
Finished products	$ 41,430	$ 41,430	$ 29,081
Work-in-process	1,186	1,186	1,648
Raw materials	32,743	32,743	35,295
Total FIFO inventory	75,359	75,359	66,024
LIFO reserve	(16,940)	(16,940)	(16,167)
Total inventory	58,419	58,419	$ 49,857
Earnings impact of LIFO inventory liquidations	$ 432	$ 605

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SAB Topic 11.F)
-URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100079-122729

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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