Note H - Employee Benefit Plans - Plan Assets (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Total plan assets		$ 103,891	$ 131,741
Total plan assets, percentage		100.00%	100.00%
Pension Plan [Member]
Total plan assets		$ 103,891	$ 131,741	$ 129,348
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total plan assets		85,665	123,162
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total plan assets		14,271	4,851
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total plan assets		0	0
Equity Securities [Member]
Total plan assets		$ 50,090	$ 66,324
Total plan assets, percentage		48.00%	50.00%
Equity Securities [Member] | Pension Plan [Member]
Total plan assets		$ 50,090	$ 66,324
Equity Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total plan assets		50,090	66,324
Equity Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total plan assets		0	0
Equity Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total plan assets		0	0
Debt Securities [Member]
Total plan assets		$ 49,846	$ 61,689
Total plan assets, percentage		48.00%	47.00%
Debt Securities [Member] | Pension Plan [Member]
Total plan assets		$ 49,846	$ 61,689
Debt Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total plan assets		35,575	56,838
Debt Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total plan assets		14,271	4,851
Debt Securities [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total plan assets		0	0
Other than Securities Investment [Member]
Total plan assets		$ 3,955	$ 3,728
Total plan assets, percentage		4.00%	3.00%
Investments Excluding Investments at NAV [Member] | Pension Plan [Member]
Total plan assets		$ 99,936	$ 128,013
Investments Excluding Investments at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total plan assets		85,665	123,162
Investments Excluding Investments at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total plan assets		14,271	4,851
Investments Excluding Investments at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total plan assets		0	0
Investment at NAV [Member] | Pension Plan [Member]
Total plan assets	[1]	3,955	3,728
Investment at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total plan assets	[1]	0	0
Investment at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total plan assets	[1]	0	0
Investment at NAV [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total plan assets	[1]	$ 0	$ 0

[1] Investment valued at net asset value ("NAV") are comprised of cash, cash equivalents, and short-term investments used to provide liquidity for the payment of benefits and other purposes. The commingled funds are valued at NAV based on the market value of the underlying investments, which are primarily government issued securities.