Note M - Pension and Other Postretirement Benefit Plans - Plan Assets Using Fair Value Hierarchy (Details) - USD ($) $ in Thousands		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Inputs, Level 3 [Member]
Plan Assets		$ 6,646	$ 6,095	$ 6,171
Pension Plan [Member]
Plan Assets		92,430	83,284	$ 87,291
Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets		36,654	30,026
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets		30,008	23,931
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets		0	0
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets		6,646	6,095
Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets	[1]	55,776	53,258
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets		1,043	920
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets		1,043	920
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets		0	0
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets		0	0
Investments Measured at Net Asset Value, Fixed Income Funds [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		31,627	33,032
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[2]	1,398	544
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[2]	1,398	544
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[2]	0	0
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[2]	0	0
Investments Measured at Net Asset Value, Equity Securities [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		4,282	2,840
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[2]	18,201	14,551
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[2]	18,201	14,551
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[2]	0	0
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[2]	0	0
Investments Measured at Net Asset Value, Real Estate [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		7,747	7,186
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[3]	9,366	7,916
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[3]	9,366	7,916
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[3]	0	0
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[3]	0	0
Investments Measured at Net Asset Value, Hedge Funds [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		12,120	10,200
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[4]	6,646	6,095
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[4]	0	0
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[4]	0	0
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[4]	$ 6,646	$ 6,095

[1] In accordance with ASC 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets at the end of the year.

[2] Common stock is valued at the closing price reported on the active market on which the individual securities are traded. These securities include U.S. equity securities invested in companies that are traded on exchanges inside the U.S. and international equity securities invested in companies that are traded on exchanges outside the U.S.

[3] Mutual funds are valued at the daily closing price as reported by the fund. Mutual funds held by the Company’s funded benefit plans are open-end mutual funds that are registered with the Securities Exchange Commission. These funds are required to publish their daily net asset value (“NAV”) and to transact at that price. The mutual funds held by the Company’s funded benefit plans are deemed to be actively traded.

[4] Annuity contracts represent contractual agreements in which payments are made to an insurance company, which agrees to pay out an income or lump sum amount at a later date. Annuity contracts are valued at fair value using the net present value of future cash flows.