Business Segment and Foreign Operations (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
Schedule of net sales to external customers by geographic area
Total net sales	$ 124,871	$ 123,527	$ 345,307	$ 350,985
United States [Member]
Schedule of net sales to external customers by geographic area
Total net sales	48,985	37,246	123,239	98,668
People's Republic of China [Member]
Schedule of net sales to external customers by geographic area
Total net sales	21,300	30,290	56,060	83,076
Argentina [Member]
Schedule of net sales to external customers by geographic area
Total net sales	2,279	2,409	6,841	4,673
Australia [Member]
Schedule of net sales to external customers by geographic area
Total net sales	347	522	895	1,078
Brazil [Member]
Schedule of net sales to external customers by geographic area
Total net sales	4,922	3,912	10,800	6,326
Canada [Member]
Schedule of net sales to external customers by geographic area
Total net sales	2,665	4,665	8,777	9,882
France [Member]
Schedule of net sales to external customers by geographic area
Total net sales	1,034	1,254	1,860	3,362
Germany [Member]
Schedule of net sales to external customers by geographic area
Total net sales	1,505	1,635	5,451	4,761
Israel [Member]
Schedule of net sales to external customers by geographic area
Total net sales	80	1,018	3,940	2,628
Italy [Member]
Schedule of net sales to external customers by geographic area
Total net sales	299	371	1,051	1,667
Japan [Member]
Schedule of net sales to external customers by geographic area
Total net sales	9,252	10,647	29,288	31,922
Korea [Member]
Schedule of net sales to external customers by geographic area
Total net sales	3,060	1,296	8,423	6,160
Malaysia [Member]
Schedule of net sales to external customers by geographic area
Total net sales	3,157	3,444	9,588	12,942
Netherlands [Member]
Schedule of net sales to external customers by geographic area
Total net sales	587	559	2,168	1,149
Portugal [Member]
Schedule of net sales to external customers by geographic area
Total net sales	278	663	773	1,463
Singapore [Member]
Schedule of net sales to external customers by geographic area
Total net sales	4,272	1,027	10,913	13,055
South Africa [Member]
Schedule of net sales to external customers by geographic area
Total net sales	1,355	2,833	3,091	5,211
Spain [Member]
Schedule of net sales to external customers by geographic area
Total net sales	1,027	872	2,735	2,925
Taiwan [Member]
Schedule of net sales to external customers by geographic area
Total net sales	2,189	5,169	8,248	16,515
Thailand [Member]
Schedule of net sales to external customers by geographic area
Total net sales	3,927	2,213	14,179	9,684
United Kingdom [Member]
Schedule of net sales to external customers by geographic area
Total net sales	7,018	5,038	18,843	16,567
All other [Member]
Schedule of net sales to external customers by geographic area
Total net sales	5,333	6,444	18,144	17,271
Total international [Member]
Schedule of net sales to external customers by geographic area
Total net sales	$ 75,886	$ 86,281	$ 222,068	$ 252,317