Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension and other post-retirement actuarial items [Abstract]
Beginning Balance	$ (119,990)	$ (105,910)	$ (122,182)
Before-Tax Amount	(54,053)	(30,213)	6,231
Tax Effect	16,975	4,494	(832)
Net-of-Tax Amount	(37,078)	(25,719)	5,399
VPG Spin-off	0	1,079	0
Ending Balance	(157,068)	(130,550)	(116,783)
Reclassification adjustment for recognition of actuarial items [Abstract]
Before-Tax Amount	12,192	10,498	10,831
Tax Effect	(4,321)	62	42
Net-of-Tax Amount	7,871	10,560	10,873
VPG Spin-off recognition of actuarial items	0	0	0
Ending Balance	7,871	10,560	10,873
Currency translation adjustment [Abstract]
Beginning Balance	179,335	208,341	198,261
Before-Tax Amount	(26,441)	(41,930)	10,080
Tax Effect	0	0	0
Net-of-Tax Amount	(26,441)	(41,930)	10,080
VPG Spin-off	0	12,924	0
Ending Balance	152,894	179,335	208,341
Unrealized gain (loss) on available-for-sale securities [Abstract]
Beginning Balance	1,146	544	(110)
Before-Tax Amount	(1,639)	927	1,006
Tax Effect	574	(325)	(352)
Net-of-Tax Amount	(1,065)	602	654
VPG Spin-off	0	0	0
Ending Balance	81	1,146	544
Other Comprehensive Income (Loss) - Total [Abstract]
Beginning Balance	60,491	102,975	75,969
Before-Tax Amount	(69,941)	(60,718)	28,148
Tax Effect	13,228	4,231	(1,142)
Net-of-Tax Amount	(56,713)	(56,487)	27,006
VPG Spin-off	0	14,003	0
Ending Balance	$ 3,778	$ 60,491	$ 102,975