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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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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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Disclosure About Segments of Enterprise and Related Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Segment information [Line Items]
Number of operating segments	4
Revenue by segment [Abstract]
Revenue	$ 106,309	$ 150,102
Depreciation and Amortization [Abstract]
Depreciation and Amortization	9,143	9,749
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	7,331	35,601
Other expense	(1,335)	(737)
Income before provision for income taxes	5,996	34,864
Segment Assets	956,552	926,530	948,131
Expenditures for Property, Plant & Equipment	5,924	7,677
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	100.00%	100.00%
Revenue by product line [Abstract]
Revenue	106,309	150,102
United States [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	57.00%	57.00%
Foreign net sales [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	43.00%	43.00%
Advanced Ceramic Operations [Member]
Revenue by segment [Abstract]
Revenue	48,705	76,630
Depreciation and Amortization [Abstract]
Depreciation and Amortization	2,293	2,871
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	3,395	17,014
Segment Assets	489,861	453,886
Expenditures for Property, Plant & Equipment	1,823	1,400
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	45.00%	49.00%
Revenue by product line [Abstract]
Revenue	48,705	76,630
Advanced Ceramic Operations [Member] \| United States [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	38.00%	43.00%
Advanced Ceramic Operations [Member] \| Foreign net sales [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	7.00%	6.00%
Advanced Ceramic Operations [Member] \| Defense [Member]
Revenue by segment [Abstract]
Revenue	29,386	56,427
Revenue by product line [Abstract]
Revenue	29,386	56,427
Advanced Ceramic Operations [Member] \| Industrial [Member]
Revenue by segment [Abstract]
Revenue	9,273	7,204
Revenue by product line [Abstract]
Revenue	9,273	7,204
Advanced Ceramic Operations [Member] \| Energy [Member]
Revenue by segment [Abstract]
Revenue	4,320	8,423
Revenue by product line [Abstract]
Revenue	4,320	8,423
Advanced Ceramic Operations [Member] \| Automotive/Diesel [Member]
Revenue by segment [Abstract]
Revenue	1,828	2,502
Revenue by product line [Abstract]
Revenue	1,828	2,502
Advanced Ceramic Operations [Member] \| Commercial (Orthodontics) [Member]
Revenue by segment [Abstract]
Revenue	3,898	2,074
Revenue by product line [Abstract]
Revenue	3,898	2,074
ESK Ceramics [Member]
Revenue by segment [Abstract]
Revenue	42,408	40,123
Depreciation and Amortization [Abstract]
Depreciation and Amortization	2,975	3,139
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	7,177	7,805
Segment Assets	172,755	185,070
Expenditures for Property, Plant & Equipment	2,183	678
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	34.00%	26.00%
Revenue by product line [Abstract]
Revenue	42,408	40,123
ESK Ceramics [Member] \| United States [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	5.00%	6.00%
ESK Ceramics [Member] \| Foreign net sales [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	29.00%	20.00%
Thermo Materials [Member]
Revenue by segment [Abstract]
Revenue	14,866	31,111
Depreciation and Amortization [Abstract]
Depreciation and Amortization	2,020	1,686
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	(1,783)	10,854
Segment Assets	171,672	161,065
Expenditures for Property, Plant & Equipment	559	4,949
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	14.00%	20.00%
Revenue by product line [Abstract]
Revenue	14,866	31,111
Thermo Materials [Member] \| United States [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	9.00%	4.00%
Thermo Materials [Member] \| Foreign net sales [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	5.00%	16.00%
Boron [Member]
Revenue by segment [Abstract]
Revenue	7,203	7,940
Depreciation and Amortization [Abstract]
Depreciation and Amortization	1,855	2,053
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	(876)	0
Segment Assets	122,264	126,509
Expenditures for Property, Plant & Equipment	1,359	650
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	7.00%	5.00%
Revenue by product line [Abstract]
Revenue	7,203	7,940
Boron [Member] \| United States [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	5.00%	4.00%
Boron [Member] \| Foreign net sales [Member]
Revenue by geographic concentration [Line Items]
Percentage of net sales from external customers	2.00%	1.00%
Inter-segment Elimination [Member]
Revenue by segment [Abstract]
Revenue	(6,873)	(5,702)
Segment Income (Loss) from Operations and Income before Provision for Income Taxes [Abstract]
Segment Income (loss) from operations	(582)	(72)
Revenue by product line [Abstract]
Revenue	$ (6,873)	$ (5,702)