CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 198,085	$ 139,959	$ 303,790	$ 271,393
Foreign currency translation adjustments [Abstract]
Foreign currency translation (losses) gains	(13,978)	(65,159)	9,722	(12,851)
Reclassification of foreign currency translation losses to earnings	0	0	25,339	0
Total foreign currency translation adjustment	(13,978)	(65,159)	35,061	(12,851)
Pension and other postretirement benefit plans [Abstract]
Amortization of actuarial losses included in net periodic pension cost	77	1,068	252	3,007
Amortization of prior service cost included in net periodic pension cost	512	1,252	1,084	1,995
Total pension and other postretirement benefit plans	589	2,320	1,336	5,002
Changes in fair value of cash flow hedges [Abstract]
Unrealized net (losses) gains arising during period	(3,362)	2,105	(768)	3,467
Net losses (gains) reclassified into earnings	(416)	(457)	(646)	(710)
Total cash flow hedges	(3,778)	1,648	(1,414)	2,757
Other comprehensive (loss) earnings	(17,167)	(61,191)	34,983	(5,092)
Comprehensive earnings	$ 180,918	$ 78,768	$ 338,773	$ 266,301