CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 139,959	$ 164,058	$ 271,393	$ 336,305
Foreign currency translation adjustments [Abstract]
Foreign currency translation gains (losses)	(65,159)	26,174	(12,851)	66,071
Reclassification of foreign currency translation losses to earnings	0	0	0	3,875
Reclassification of foreign currency translation losses to earnings	0	0	0	3,875
Total foreign currency translation adjustment	(65,159)	26,174	(12,851)	69,946
Pension and other postretirement benefit plans [Abstract]
Amortization of actuarial losses included in net periodic pension cost	1,068	1,353	3,007	2,691
Amortization of prior service cost included in net periodic pension cost	1,252	702	1,995	1,404
Total pension and other postretirement benefit plans	2,320	2,055	5,002	4,095
Changes in fair value of cash flow hedges [Abstract]
Unrealized net gains (losses) arising during period	2,105	(1,876)	3,467	(1,798)
Net (gains) losses reclassified into earnings	(457)	159	(710)	(58)
Total cash flow hedges	1,648	(1,717)	2,757	(1,856)
Other comprehensive income loss other adjustment, net of tax	0	(578)	0	(241)
Other comprehensive (loss) earnings	(61,191)	25,934	(5,092)	71,944
Comprehensive earnings	$ 78,768	$ 189,992	$ 266,301	$ 408,249