Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
NET EARNINGS	$ 231,420	$ 32,115	$ 61,202
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(6)	(2)	1,467
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	14,315	(25,638)	20,800
TOTAL COMPREHENSIVE INCOME, net of tax	247,996	15,325	90,698
Pension Plans [Member]
Other comprehensive income (loss), net of tax	16,262	(16,941)	27,890
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	14,087	(25,712)	20,793
Income tax (expense) or benefit	(4,881)	5,008	(8,431)
Post-Retirement Plans [Member]
Other comprehensive income (loss), net of tax	320	153	139
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	228	74	7
Income tax (expense) or benefit	$ (96)	$ (45)	$ (40)