Pensions and Other Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	$ 9,175
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	849	849
Interest cost	4,602	5,034
Expected return on assets	(4,168)	(3,981)
Transition obligation	19	22
Prior service cost/(credit)	9	9
Net actuarial loss	1,773	1,422
Settlement charge	9,175
Net periodic benefit costs	12,259	3,355
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	268	228
Interest cost	922	955
Expected return on assets
Transition obligation
Prior service cost/(credit)	(917)	(917)
Net actuarial loss	804	753
Settlement charge
Net periodic benefit costs	1,077	1,019
Sweden Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	$ 9,200