Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined benefit plans:
Multiemployer pension plans	$ 570	$ 667	$ 1,876	$ 2,334
Defined contribution pension plans	2,619	3,322	8,884	10,321
U. S. Plans
Defined benefit plans:
Service cost	722	558	2,167	1,675
Interest cost	3,089	3,217	9,268	9,651
Expected return on plan assets	(4,203)	(4,196)	(12,609)	(12,590)
Recognized prior service costs	20	22	60	68
Recognized loss	1,230	838	3,689	2,514
Defined Benefit Plan, Amortization of Transition Obligations (Assets)			0	0
Defined benefit plans net periodic pension cost	858	439	2,575	1,318
Defined benefit pension plan	567	5,909	1,841	7,057
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year			600
International Plans
Defined benefit plans:
Service cost	428	394	1,320	1,213
Interest cost	9,146	11,024	27,475	32,948
Expected return on plan assets	(12,630)	(12,743)	(37,914)	(38,039)
Recognized prior service costs	47	46	144	138
Recognized loss	4,244	3,596	12,700	10,732
Defined Benefit Plan, Amortization of Transition Obligations (Assets)			0	56
Defined benefit plans net periodic pension cost	1,235	2,317	3,725	7,048
Defined benefit pension plan	$ 3,935	$ 4,226	24,166	$ 25,963
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year			$ 4,200