Net Periodic Benefit Cost (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
United States Pension Plans of US Entity, Defined Benefit [Member]
Components of Net periodic pension cost for the Company's defined benefit pension plans and U.S. post-retirement medical plan
Service cost, net	$ 123	$ 114	$ 247	$ 228
Interest cost on projected benefit obligations	1,439	1,523	2,878	3,046
Expected return on plan assets	(1,788)	(1,741)	(3,576)	(3,483)
Net amortization and deferral	0	0	0	0
Recognition of actuarial losses/(gains)	1,945	1,916	3,891	3,832
Net periodic pension cost/(credit)	1,719	1,812	3,440	3,623
Net Periodic Benefit Cost (Textuals) [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year			5,100
Foreign Pension Plans, Defined Benefit [Member]
Components of Net periodic pension cost for the Company's defined benefit pension plans and U.S. post-retirement medical plan
Service cost, net	4,257	3,588	8,627	7,226
Interest cost on projected benefit obligations	4,822	5,535	9,705	11,139
Expected return on plan assets	(8,570)	(8,141)	(17,262)	(16,375)
Net amortization and deferral	(979)	(353)	(1,973)	(710)
Recognition of actuarial losses/(gains)	1,823	609	3,669	1,223
Net periodic pension cost/(credit)	1,353	1,238	2,766	2,503
Net Periodic Benefit Cost (Textuals) [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year			20,600
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Components of Net periodic pension cost for the Company's defined benefit pension plans and U.S. post-retirement medical plan
Service cost, net	54	83	108	166
Interest cost on projected benefit obligations	101	135	202	270
Expected return on plan assets	0	0	0	0
Net amortization and deferral	22	0	43	0
Recognition of actuarial losses/(gains)	(247)	(188)	(494)	(377)
Net periodic pension cost/(credit)	(70)	30	(141)	59
Net Periodic Benefit Cost (Textuals) [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year			$ 1,100