CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 171,597	$ 282,425	$ 107,223
Other comprehensive (loss) income, net of tax:
Change in minimum liability for pension plans, net of tax effects of ($24), ($138) and $477, respectively	(58)	(338)	1,271
Fair value adjustment in interest rate swap contracts, net of tax effects of $265, $0 and $1, respectively	(796)	0	187
Foreign currency translation, reclassification	0	0	(494)
Gain/Loss on held-for-sale securities	4	0	(4)
Foreign currency translation adjustments	(16,003)	(35,394)	51,631
Total other comprehensive (loss) income	(16,853)	(35,732)	52,591
Comprehensive income	$ 154,744	$ 246,693	$ 159,814