Disclosure About Segments of Enterprise and Related Information (Segment Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 segment	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of operating segments			4
Revenue from external customers	$ 130,643	$ 145,376	$ 236,952	$ 295,478
Depreciation and Amortization	9,072	9,931	18,215	19,678
Income from Operations	12,915	29,449	20,246	65,050
Other Income (Expense)	(1,488)	(115)	(2,823)	(852)
Income before Provision for Income Taxes	11,427	29,334	17,423	64,198
Segment Assets	940,140	955,915	940,140	955,915	948,131
Expenditures for Property, Plant & Equipment	4,618	9,394	10,524	17,055
Advanced Ceramic Operations [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	70,395	66,637	119,100	143,267
Depreciation and Amortization	2,358	2,514	4,651	5,385
Income from Operations	9,749	14,041	13,144	31,055
Segment Assets	486,404	468,385	486,404	468,385
Expenditures for Property, Plant & Equipment	911	2,076	2,724	3,475
ESK Ceramics [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	37,524	45,880	79,932	86,003
Depreciation and Amortization	2,925	3,276	5,900	6,415
Income from Operations	4,066	9,201	11,243	17,006
Segment Assets	162,998	190,440	162,998	190,440
Expenditures for Property, Plant & Equipment	1,501	1,322	3,675	1,984
Thermo Materials [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	15,290	29,295	30,156	60,406
Depreciation and Amortization	1,934	2,094	3,954	3,778
Income from Operations	(2,474)	6,066	(4,257)	16,920
Segment Assets	164,637	169,420	164,637	169,420
Expenditures for Property, Plant & Equipment	351	4,672	911	9,622
Boron [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	13,820	11,420	21,023	19,360
Depreciation and Amortization	1,855	2,047	3,710	4,100
Income from Operations	1,930	726	1,054	726
Segment Assets	126,101	127,670	126,101	127,670
Expenditures for Property, Plant & Equipment	1,855	1,324	3,214	1,974
Inter-segment Elimination [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	(6,386)	(7,856)	(13,259)	(13,558)
Income from Operations	$ (356)	$ (585)	$ (938)	$ (657)

Total expenditures for additions to long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets of the reportable segment; if the amount: (a) is included in the determination of segment assets reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in the determination of segment assets.

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