Note H - Employee Benefit Plans - Fair Values by Asset Category of Defined Benefit Pension Plan (Details) - USD ($) $ in Thousands		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Fair value by asset category		$ 1,429	$ 1,339	$ 1,369
Fair Value, Inputs, Level 1 [Member]
Fair value by asset category		1,429
Fair Value, Inputs, Level 2 [Member]
Fair value by asset category
Fair Value, Inputs, Level 3 [Member]
Fair value by asset category
Cash and Cash Equivalents [Member]
Fair value by asset category		9
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value by asset category		9
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value by asset category
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value by asset category
Commodities and Other [Member]
Fair value by asset category		172
Commodities and Other [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value by asset category		172
Commodities and Other [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value by asset category
Commodities and Other [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value by asset category
Equity Securities [Member]
Fair value by asset category	[1]	882
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value by asset category	[1]	882
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value by asset category	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value by asset category	[1]
Debt Securities [Member]
Fair value by asset category	[2]	366
Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value by asset category	[2]	366
Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value by asset category	[2]
Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value by asset category	[2]

[1] This category is comprised of publicly traded funds, of which 79% are large-cap funds, 13% are developed market funds, and 8% are emerging markets equity funds.

[2] This category is comprised of publicly traded funds, of which 82% are U.S. fixed income funds and 18% are developed market fixed income funds.