Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined benefit plans:
Multiemployer pension plans	$ 741	$ 966	$ 1,306	$ 1,667
Defined contribution pension plans	2,817	2,930	6,265	6,999
U. S. Plans
Defined benefit plans:
Service cost	722	558	1,444	1,116
Interest cost	3,089	3,217	6,179	6,434
Expected return on plan assets	(4,203)	(4,196)	(8,406)	(8,392)
Recognized prior service costs	20	22	40	44
Recognized loss	1,230	838	2,459	1,676
Settlement/curtailment losses	0	0	0	0
Defined benefit plans net periodic pension cost	858	439	1,716	878
Defined benefit pension plan	592	582	1,274	1,148
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year			1,200
International Plans
Defined benefit plans:
Service cost	453	411	892	818
Interest cost	9,140	11,012	18,329	21,924
Expected return on plan assets	(12,611)	(12,708)	(25,285)	(25,296)
Recognized prior service costs	48	47	97	93
Recognized loss	4,223	3,583	8,457	7,136
Settlement/curtailment losses	0	56	0	56
Defined benefit plans net periodic pension cost	1,253	2,401	2,490	4,731
Defined benefit pension plan	$ 4,165	$ 4,316	20,231	$ 21,737
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year			$ 9,100