Note 12 - Fair Value of Assets and Liabilities - Fair Value Measurements, Recorded (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Derivative Asset	$ 766
Total assets at fair value	16,896	$ 9,424
Total liabilities recorded at fair value	5,224
Supplemental Executive Retirement Plan [Member]
Derivative Asset	11,617	7,676
Metal Swaps [Member]
Derivative Asset	4,458
Derivative liability	5,224
Interest Rate Swap [Member]
Derivative Asset	55	1,748
Fair Value, Inputs, Level 1 [Member]
Derivative Asset	0
Total assets at fair value	11,617	7,676
Total liabilities recorded at fair value	0
Fair Value, Inputs, Level 1 [Member] | Supplemental Executive Retirement Plan [Member]
Derivative Asset	11,617	7,676
Fair Value, Inputs, Level 1 [Member] | Metal Swaps [Member]
Derivative Asset	0
Derivative liability	0
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member]
Derivative Asset	0	0
Fair Value, Inputs, Level 2 [Member]
Derivative Asset	766
Total assets at fair value	5,279	1,748
Total liabilities recorded at fair value	5,224
Fair Value, Inputs, Level 2 [Member] | Supplemental Executive Retirement Plan [Member]
Derivative Asset	0	0
Fair Value, Inputs, Level 2 [Member] | Metal Swaps [Member]
Derivative Asset	4,458
Derivative liability	5,224
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Derivative Asset	55	1,748
Fair Value, Inputs, Level 3 [Member]
Derivative Asset	0
Total assets at fair value	0	0
Total liabilities recorded at fair value	0
Fair Value, Inputs, Level 3 [Member] | Supplemental Executive Retirement Plan [Member]
Derivative Asset	0	0
Fair Value, Inputs, Level 3 [Member] | Metal Swaps [Member]
Derivative Asset	0
Derivative liability	0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member]
Derivative Asset	$ 0	$ 0