CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net earnings	$ 508,892	$ 869,829	$ 775,235
Foreign currency translation adjustments [Abstract]
Foreign currency translation losses	(106,526)	(117,302)	(144,643)
Reclassification of foreign currency translation losses (gains) to earnings	823	(3,092)	(6,300)
Total foreign currency translation adjustments	(105,703)	(120,394)	(150,943)
Pension and other postretirement benefit plans [Abstract]
Actuarial (losses) gains	(7,928)	4,492	(60,766)
Prior service (cost) credit	(776)	4,171	(354)
Amortization of actuarial losses including in net periodic pension cost	5,683	10,280	5,792
Amortization of prior service costs included in net periodic pension cost	4,397	4,993	5,617
Total pension and other postretirement benefit plans	1,376	23,936	(49,711)
Changes in fair value of cash flow hedges [Abstract]
Unrealized net gains (losses)	144	(328)	(137)
Net losses (gains) reclassified into earnings	415	(108)	(107)
Changes in fair value of cash flow hedges, net of tax	559	(436)	(244)
Other	(985)	1,252	939
Other comprehensive loss, net of tax	(104,753)	(95,642)	(199,959)
Comprehensive earnings	$ 404,139	$ 774,187	$ 575,276