Health Care, Pension and Other Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Domestic Defined Benefit Pension Plans [Member]
Net periodic benefit cost (credit):
Service cost	$ 5,741	$ 5,754	$ 16,719	$ 17,263
Interest cost	6,587	6,236	19,873	18,710
Expected return on assets	(12,514)	(13,023)	(37,648)	(39,071)
Amortization of:
Prior service cost (credit)	302	327	904	982
Actuarial loss	1,094	844	3,399	2,530
Net periodic benefit cost (credit)	1,210	138	3,247	414
Foreign Defined Benefit Pension Plans [Member]
Net periodic benefit cost (credit):
Service cost	955	1,326	3,494	3,976
Interest cost	1,788	2,271	5,949	6,813
Expected return on assets	(1,581)	(2,431)	(5,273)	(7,292)
Amortization of:
Actuarial loss	230	485	1,095	1,454
Settlement costs			4,038
Net periodic benefit cost (credit)	1,392	1,651	9,303	4,951
Postretirement Benefits Other than Pensions [Member]
Net periodic benefit cost (credit):
Service cost	562	621	1,684	1,863
Interest cost	2,752	2,795	8,257	8,386
Amortization of:
Prior service cost (credit)	(1,645)	(1,132)	(4,935)	(3,396)
Actuarial loss		253		759
Net periodic benefit cost (credit)	$ 1,669	$ 2,537	$ 5,006	$ 7,612