CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 164,058	$ 118,290	$ 336,305	$ 217,646
Foreign currency translation adjustments [Abstract]
Foreign currency translation gains during period	26,174	(41,992)	66,071	(33,223)
Reclassification of foreign currency translation losses to earnings upon sale of subsidiary	0	0	3,875	0
Total foreign currency translation adjustment	26,174	(41,992)	69,946	(33,223)
Pension and other postretirement benefit plans [Abstract]
Amortization of actuarial losses included in net periodic pension cost	1,353	1,416	2,691	2,825
Amortization of prior service cost included in net periodic pension cost	702	1,040	1,404	2,081
Total pension and other postretirement benefit plans	2,055	2,456	4,095	4,906
Changes in fair value of cash flow hedges [Abstract]
Unrealized net gains (losses) arising during period	(1,876)	(162)	(1,798)	(211)
Net losses reclassified into earnings	159	213	(58)	166
Total cash flow hedges	(1,717)	51	(1,856)	(45)
Other	(578)	(448)	(241)	1,392
Other comprehensive earnings (loss)	25,934	(39,933)	71,944	(26,970)
Comprehensive earnings	$ 189,992	$ 78,357	$ 408,249	$ 190,676