Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Foreign currency translation adjustments [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	$ 103,214	$ (86,876)	$ (108,748)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	43,842	(18,827)	(11,646)
Total foreign currency translation adjustments	147,056	(105,703)	(120,394)
Pension and other postretirement benefit plans [Abstract]
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	28,784	5,936	35,727
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	(7,397)	(4,560)	(11,791)
Pension and other postretirement benefit plans	21,387	1,376	23,936
Changes in fair value of cash flow hedges [Abstract]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	(3,678)	860	(671)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	1,287	(301)	235
Changes in fair value of cash flow hedges, net of tax	(2,391)	559	(436)
Other Comprehensive Income Other Adjustment Net Of Tax [Abstract]
Other Comprehensive Income Loss Adjustment Before Tax	(1,687)	(1,119)	1,423
Other Comprehensive Income Loss Other Adjustment Tax	202	134	(171)
Other comprehensive income loss other adjustment, net of tax	(1,485)	(985)	1,252
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Other Comprehensive Income (Loss), before Tax	126,633	(81,199)	(72,269)
Other Comprehensive Income (Loss), Tax	37,934	(23,554)	(23,373)
Other Comprehensive Income (Loss), Net of Tax	164,567	(104,753)	(95,642)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(93,925)	(240,981)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(100,538)	(121,925)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(296)	3,580
Accumulated Other Comprehensive Income (Loss), Net of Tax	(194,759)	(359,326)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net earnings	811,665	508,892	869,829
Other comprehensive earnings (loss)	164,567	(104,753)	(95,642)
Comprehensive earnings	976,232	404,139	774,187
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]
Amortization of actuarial losses	7,735	8,544	15,527
Amortization of prior service costs and transition obligation	4,424	6,609	7,541
Settlements and Curtailments	(3,844)	0	0
Total before tax	8,315	15,153	23,068
Tax benefit	(2,503)	(5,073)	(7,768)
Net of tax	5,812	10,080	15,300
Other Comprehensive Income Loss Reclassification Adjustment From AOCI Derivatives Net of Tax [Abstract]
Net (gains) losses reclassified into earnings	(908)	638	(166)
Tax expense (benefit)	318	(223)	58
Net of tax	$ (590)	$ 415	$ (108)