Pension and Postretirement Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Plans [Member]
Net periodic benefit cost of pension and post retirement benefit plans
Service cost	$ 24	$ 17	$ 78	$ 91
Interest cost	276	292	863	892
Expected return on plan assets	(84)	(140)	(305)	(422)
Recognized net actuarial loss	110	1	368	342
Net periodic benefit cost	326	170	1,004	903
Postretirement Benefit Plans [Member]
Net periodic benefit cost of pension and post retirement benefit plans
Service cost	31	22	110	96
Interest cost	187	187	611	651
Expected return on plan assets	(15)	(35)	(56)	(101)
Amortization of prior service credit	(278)	(320)	(835)	(958)
Recognized net actuarial loss	101	80	410	400
Net periodic benefit cost	26	(66)	240	88
Foreign Pension Plans [Member]
Net periodic benefit cost of pension and post retirement benefit plans
Service cost	123	92	368	276
Interest cost	186	183	552	551
Expected return on plan assets	(157)	(164)	(467)	(493)
Net periodic benefit cost	$ 152	$ 111	$ 453	$ 334