Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Foreign currency translation adjustments [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax									$ (108,748)	$ (131,420)	$ 2,242
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax									(11,646)	(19,523)	2,494
Total foreign currency translation, net of tax									(120,394)	(150,943)	4,736
Pension and other postretirement benefit plans [Abstract]
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax									35,727	(70,705)	182,092
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax									(11,791)	20,994	(63,585)
Pension and other postretirement benefit plans, net of tax									23,936	(49,711)	118,507
Changes in fair value of cash flow hedges [Abstract]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax									(671)	(375)	(75)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax									235	131	26
Changes in fair value of cash flow hedges, net of tax									(436)	(244)	(49)
Other Comprehensive Income Other Adjustment Net Of Tax [Abstract]
Other Comprehensive Income Loss Adjustment Before Tax									1,423	1,067	(642)
Other Comprehensive Income Loss Other Adjustment Tax									(171)	(128)	77
Other comprehensive income loss other adjustment, net of tax									1,252	939	(565)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Other Comprehensive Income (Loss), before Tax									(72,269)	(201,433)	183,617
Other Comprehensive Income (Loss), Tax									(23,373)	1,474	(60,988)
Other Comprehensive Income (Loss), Net of Tax									(95,642)	(199,959)	122,629
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net earnings	$ 141,825	$ 186,098	$ 332,396	$ 209,510	$ 169,294	$ 231,844	$ 213,959	$ 160,138	869,829	775,235	1,003,129
Other comprehensive (loss) earnings, net of tax									(95,642)	(199,959)	122,629
Comprehensive earnings									774,187	575,276	1,125,758
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(135,278)				(14,884)				(135,278)	(14,884)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(123,301)				(147,237)				(123,301)	(147,237)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	4,006				3,190				4,006	3,190
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (254,573)				$ (158,931)				(254,573)	(158,931)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]
Amortization of actual losses									15,527	8,822	19,250
Amortization of prior service costs									7,541	8,556	8,834
Total amortization before tax									23,068	17,378	28,084
Tax provision on amortization									(7,768)	(5,969)	(9,809)
Total amortization, net of tax									15,300	11,409	18,275
Other Comprehensive Income Loss Reclassification Adjustment From AOCI Derivatives Net of Tax [Abstract]
Net (gains) losses reclassified into earnings									(166)	(164)	(130)
Tax benefit on gains reclassified into earnings									58	57	46
Net (gains) losses reclassified into earnings, net of tax									$ (108)	$ (107)	$ (84)