Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Foreign currency translation adjustments [Abstract]
Foreign currency translation adjustments, before tax	$ (52,979)	$ 13,812	$ (9,934)	$ 46,902
Foreign currency translation adjustments, tax	(12,180)	12,362	(2,917)	23,044
Total foreign currency translation adjustment	(65,159)	26,174	(12,851)	69,946
Pension and other postretirement benefit plans [Abstract]
Pension and other postretirement benefit plans, before tax	2,948	3,021	6,358	6,022
Pension and other postretirement benefit plans, tax	(628)	(966)	(1,356)	(1,927)
Total pension and other postretirement benefit plans	2,320	2,055	5,002	4,095
Changes in fair value of cash flow hedges [Abstract]
Changes in fair value of cash flow hedges, before tax	2,085	(2,642)	3,490	(2,855)
Changes in fair value of cash flow hedges, tax	(437)	925	(733)	999
Total cash flow hedges	1,648	(1,717)	2,757	(1,856)
Other comprehensive earnings other adjustment, net of tax [Abstract]
Other, before tax	0	(657)	0	(274)
Other, tax	0	79	0	33
Other comprehensive income loss other adjustment, net of tax	0	(578)	0	(241)
Total other comprehensive earnings [Abstract]
Other comprehensive earnings (loss), before Tax	(47,946)	13,534	(86)	49,795
Other comprehensive earnings (loss), tax	(13,245)	12,400	(5,006)	22,149
Other comprehensive (loss) earnings	(61,191)	25,934	(5,092)	71,944
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net earnings	139,959	164,058	271,393	336,305
Other comprehensive earnings (loss)	(61,191)	25,934	(5,092)	71,944
Comprehensive earnings	78,768	189,992	266,301	408,249
Other Comprehensive Income Loss Reclassification Adjustment from AOCI Foreign Currency Translation Net of Tax [Abstract]
Reclassification of foreign currency translation losses to earnings upon sale of subsidiary	0	0	0	(3,875)
Tax benefit	0	0	0	0
Net of tax	0	0	0	3,875
Other Comprehensive Income Loss Reclassification Adjustment From AOCI Pension And Other Postretirement Benefit Plans Net Of Tax Abstract [Abstract]
Amortization of actuarial losses	1,365	1,922	3,837	3,821
Amortization of prior service costs	1,583	1,099	2,521	2,201
Total before tax	2,948	3,021	6,358	6,022
Tax provision	(628)	(966)	(1,356)	(1,927)
Net of tax	2,320	2,055	5,002	4,095
Other Comprehensive Income Loss Reclassification Adjustment From AOCI Derivatives Net of Tax [Abstract]
Net (gains) losses reclassified into earnings	(579)	245	(899)	(89)
Tax expense (benefit)	122	(86)	189	31
Net of tax	$ (457)	$ 159	$ (710)	$ (58)