Segment Information (Income by Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 165,051us-gaap_SalesRevenueNet	$ 146,640us-gaap_SalesRevenueNet
Operating income (loss)	20,100us-gaap_OperatingIncomeLoss	21,457us-gaap_OperatingIncomeLoss
Equity income in unconsolidated joint ventures	919	977
Other income (expense), net	(129)us-gaap_OtherNonoperatingIncomeExpense	(1,191)us-gaap_OtherNonoperatingIncomeExpense
Interest income (expense), net	(1,006)	(748)
Income (loss) before income tax expense (benefit)	19,884	20,495
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales	165,051	146,640
Operating income (loss)	20,100	21,457
Equity income in unconsolidated joint ventures	919	977
Other income (expense), net	(129)	(1,191)
Interest income (expense), net	(1,006)	(748)
Income (loss) before income tax expense (benefit)	19,884	20,495
Reportable Segment [Member] \| Printed Circuit Materials [Member]
Segment Reporting Information [Line Items]
Net sales	71,287	58,536
Operating income (loss)	12,838	11,960
Reportable Segment [Member] \| High Performance Foams [Member]
Segment Reporting Information [Line Items]
Net sales	44,556	41,204
Operating income (loss)	3,015	5,729
Reportable Segment [Member] \| Power Electronics Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	38,529	40,798
Operating income (loss)	2,368	1,565
Reportable Segment [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	10,679	6,102
Operating income (loss)	$ 1,879	$ 2,203

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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The net amount of nonoperating interest income (expense).

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The net result for the period of deducting operating expenses from operating revenues.

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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