Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension and other post-retirement actuarial items [Abstract]
Beginning Balance	$ (149,197)	$ (119,990)	$ (105,910)
Before-Tax Amount	(57,072)	(54,053)	(30,213)
Tax Effect	16,626	16,975	4,494
Net-of-Tax Amount	(40,446)	(37,078)	(25,719)
VPG Spin-off	0	0	1,079
Ending Balance	(189,643)	(157,068)	(130,550)
Reclassification adjustment for recognition of actuarial items [Abstract]
Before-Tax Amount	16,059	12,192	10,498
Tax Effect	(5,372)	(4,321)	62
Net-of-Tax Amount	10,687	7,871	10,560
VPG Spin-off recognition of actuarial items	0	0	0
Ending Balance	10,687	7,871	10,560
Currency translation adjustment [Abstract]
Beginning Balance	152,894	179,335	208,341
Before-Tax Amount	14,567	(26,441)	(41,930)
Tax Effect	0	0	0
Net-of-Tax Amount	14,567	(26,441)	(41,930)
VPG Spin-off	0	0	12,924
Ending Balance	167,461	152,894	179,335
Unrealized gain (loss) on available-for-sale securities [Abstract]
Beginning Balance	81	1,146	544
Before-Tax Amount	1,834	(1,639)	927
Tax Effect	(642)	574	(325)
Net-of-Tax Amount	1,192	(1,065)	602
VPG Spin-off	0	0	0
Ending Balance	1,273	81	1,146
Other Comprehensive Income (Loss) - Total [Abstract]
Beginning Balance	3,778	60,491	102,975
Before-Tax Amount	(24,612)	(69,941)	(60,718)
Tax Effect	10,612	13,228	4,231
Net-of-Tax Amount	(14,000)	(56,713)	(56,487)
VPG Spin-off	0	0	14,003
Ending Balance	$ (10,222)	$ 3,778	$ 60,491