Note N - Pension and Other Postretirement Benefit Plans - Plan Assets Using Fair Value Hierarchy (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Inputs, Level 3 [Member]
Plan Assets		$ 6,095	$ 6,171	$ 6,113
Pension Plan [Member]
Plan Assets		83,284	87,291	$ 90,258
Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets		30,026	33,301
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets		23,931	27,130
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets		6,095	6,171
Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets	[1]	53,258	53,990
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets		920	971
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets		920	971
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets
Cash and Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets
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		33,032	33,568
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[2]	544	1,483
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[2]	544	1,483
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[2]
Company Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[2]
Investments Measured at Net Asset Value, Equity Securities [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		2,840	3,168
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[2]	14,551	16,713
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[2]	14,551	16,713
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[2]
Common Stock [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[2]
Investments Measured at Net Asset Value, Real Estate [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		7,186	7,069
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[3]	7,916	7,963
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[3]	7,916	7,963
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[3]
Mutual Fund [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[3]
Investments Measured at Net Asset Value, Hedge Funds [Member] | Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Plan Assets		10,200	10,185
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Plan Assets	[4]	6,095	6,171
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Plan Assets	[4]
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Plan Assets	[4]
Annuity Contracts [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Plan Assets	[4]	$ 6,095	$ 6,171

[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 the net present value of future cash flows.