Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Foreign currency translation adjustments [Abstract]
Foreign currency translation adjustments, before tax	$ 43,045	$ 33,090
Foreign currency translation adjustments, tax	9,263	10,682
Total foreign currency translation adjustment	52,308	43,772
Pension and other postretirement benefit plans [Abstract]
Pension and other postretirement benefit plans, before tax	3,410	3,001
Pension and other postretirement benefit plans, tax	(728)	(961)
Total pension and other postretirement benefit plans	2,682	2,040
Changes in fair value of cash flow hedges [Abstract]
Changes in fair value of cash flow hedges, before tax	1,404	(213)
Changes in fair value of cash flow hedges, tax	(295)	74
Total cash flow hedges	1,109	(139)
Other comprehensive earnings other adjustment, net of tax [Abstract]
Other, before tax	0	383
Other, tax	0	(46)
Other comprehensive income loss other adjustment, net of tax	0	337
Total other comprehensive earnings [Abstract]
Other comprehensive earnings (loss), before Tax	47,859	36,261
Other comprehensive earnings (loss), tax	8,240	9,749
Other comprehensive earnings	56,099	46,010
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net earnings	131,435	172,247
Other comprehensive earnings (loss)	56,099	46,010
Comprehensive earnings	187,534	218,257
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	(3,875)
Tax benefit	0	0
Net of tax	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	2,471	1,899
Amortization of prior service costs	939	1,102
Total before tax	3,410	3,001
Tax provision	(728)	(961)
Net of tax	2,682	2,040
Other Comprehensive Income Loss Reclassification Adjustment From AOCI Derivatives Net of Tax [Abstract]
Net (gains) losses reclassified into earnings	(320)	(334)
Tax expense (benefit)	67	117
Net of tax	$ (253)	$ (217)