CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 157,305	$ 178,912	$ 428,698	$ 515,217
Foreign currency translation adjustments [Abstract]
Foreign currency translation (losses) gains	(13,567)	93,269	(26,418)	159,340
Reclassification of foreign currency translation losses to earnings	0	0	0	3,875
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax	0	0	0	(3,875)
Total foreign currency translation adjustment	(13,567)	93,269	(26,418)	163,215
Pension and other postretirement benefit plans [Abstract]
Amortization of actuarial losses included in net periodic pension cost	402	1,375	3,409	4,066
Amortization of prior service cost included in net periodic pension cost	704	700	2,699	2,104
Total pension and other postretirement benefit plans	1,106	2,075	6,108	6,170
Changes in fair value of cash flow hedges [Abstract]
Unrealized net (losses) gains arising during period	(1,449)	(192)	2,019	(1,989)
Net losses (gains) reclassified into earnings	364	(271)	(347)	(329)
Total cash flow hedges	(1,085)	(463)	1,672	(2,318)
Other comprehensive income loss other adjustment, net of tax	0	272	0	31
Other comprehensive (loss) earnings	(13,546)	95,153	(18,638)	167,098
Comprehensive earnings	$ 143,759	$ 274,065	$ 410,060	$ 682,315