Note 12- Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Balance	$ 1,760,787	$ 1,713,785	$ 1,696,534
Other comprehensive income	30,904	4,433	4,421
Balance	1,978,967	1,760,787	1,713,785
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	(4,675)	7,632	(348)
Other comprehensive income	13,837	(12,307)	7,980
Balance	9,162	(4,675)	7,632
Balance, beginning	4,689	0	0
Change , tax	(5,233)	4,689	0
Balance, ending	(544)	4,689	0
Accumulated Defined Benefit Plans Adjustment, Net Transition Attributable to Parent [Member]
Balance	(23,781)	(40,521)	(36,962)
Other comprehensive income	(17,067)	16,740	(3,559)
Balance	(6,714)	(23,781)	(40,521)
Balance, beginning	6,196	12,575	12,575
Change , tax	(6,454)	(6,379)	0
Balance, ending	(258)	6,196	12,575
AOCI Attributable to Parent [Member]
Balance	(28,456)	(32,889)	(37,310)
Other comprehensive income	30,904	4,433	4,421
Balance	(2,448)	(28,456)	(32,889)
Balance, beginning	10,885	12,575	12,575
Change , tax	(11,687)	(1,690)	0
Balance, ending	$ (802)	$ 10,885	$ 12,575