Note N - Pension and Other Postretirement Benefit Plans - Pension Plan Weighted-Average Asset Allocations (Details)	Jun. 30, 2020	Jun. 30, 2019
Target Allocation	100.00%
Actual Allocation	100.00%	100.00%
Equity Securities [Member]
Target Allocation	51.00%
Actual Allocation	47.00%	49.00%
Debt Securities [Member]
Target Allocation	40.00%
Actual Allocation	44.00%	42.00%
Real Estate [Member]
Target Allocation	9.00%
Actual Allocation	9.00%	9.00%

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant