Employee Benefits Plans (Details 12) (Other Postretirement Benefits [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Postretirement Benefits [Member]
Benefit Obligations associated with postretirement benefit plans
Benefit obligations at January 1	$ 40,599	$ 42,992
Service cost	981	1,095	1,294
Interest Cost	1,580	1,980	2,503
Actuarial gain	(9,332)	(1,746)
Benefits paid	(2,515)	(3,947)
Foreign currency exchange rate changes	(525)	225
Benefit obligations at December 31	$ 30,788	$ 40,599	$ 42,992