Rationalizations and Impairments (Rationalization Costs Incurred) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Rationalization Plan
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	$ 6,503	$ 17,855
Rationalization Plan \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	433	17,433
Inventory loss	742	805
Fixed asset write-offs and other	1,144	(494)
Rationalization Plan \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	621
Rationalization Plan \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	1,069	25
Rationalization Plan \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	75
Rationalization Plan \| Industrial Materials
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	1,693	17,480
Rationalization Plan \| Industrial Materials \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	433	17,020
Inventory loss	(61)	815
Fixed asset write-offs and other	1,243	(494)
Rationalization Plan \| Industrial Materials \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0
Rationalization Plan \| Industrial Materials \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	0	25
Rationalization Plan \| Industrial Materials \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	25
Rationalization Plan \| Engineered Solutions
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	3,123	375
Rationalization Plan \| Engineered Solutions \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0	413
Inventory loss	803	(10)
Fixed asset write-offs and other	(99)
Rationalization Plan \| Engineered Solutions \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0
Rationalization Plan \| Engineered Solutions \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	3	0
Rationalization Plan \| Engineered Solutions \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	50
Rationalization Plan \| Corporate, R&D and Other
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	1,687	0
Rationalization Plan \| Corporate, R&D and Other \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0	0
Inventory loss	0	0
Fixed asset write-offs and other	0	0
Rationalization Plan \| Corporate, R&D and Other \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	621
Rationalization Plan \| Corporate, R&D and Other \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	1,066	0
Rationalization Plan \| Corporate, R&D and Other \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	0
Rationalization Plan \| Employee Severance \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	2,419	86
Rationalization Plan \| Employee Severance \| Industrial Materials \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	53	114
Rationalization Plan \| Employee Severance \| Engineered Solutions \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	2,366	(28)
Rationalization Plan \| Employee Severance \| Corporate, R&D and Other \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	0	0
2013 Rationalization Initiatives
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	1,736	17,855
2013 Rationalization Initiatives \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	433	17,433
Inventory loss	(61)	805
Fixed asset write-offs and other	1,252	(494)
2013 Rationalization Initiatives \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other		25
2013 Rationalization Initiatives \| Industrial Materials
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	1,727	17,480
2013 Rationalization Initiatives \| Industrial Materials \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	433	17,020
Inventory loss	(61)	815
Fixed asset write-offs and other	1,243	(494)
2013 Rationalization Initiatives \| Industrial Materials \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other		25
2013 Rationalization Initiatives \| Engineered Solutions
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	9	375
2013 Rationalization Initiatives \| Engineered Solutions \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0	413
Inventory loss	0	(10)
Fixed asset write-offs and other	9	0
2013 Rationalization Initiatives \| Engineered Solutions \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other		0
2013 Rationalization Initiatives \| Corporate, R&D and Other
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	0	0
2013 Rationalization Initiatives \| Corporate, R&D and Other \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0	0
Inventory loss	0	0
Fixed asset write-offs and other	0	0
2013 Rationalization Initiatives \| Corporate, R&D and Other \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other		0
2013 Rationalization Initiatives \| Employee Severance \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	87	86
2013 Rationalization Initiatives \| Employee Severance \| Industrial Materials \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	87	114
2013 Rationalization Initiatives \| Employee Severance \| Engineered Solutions \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	0	(28)
2013 Rationalization Initiatives \| Employee Severance \| Corporate, R&D and Other \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	0	0
2013 Rationalization Initiatives \| Contract Terminations \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	25
2013 Rationalization Initiatives \| Contract Terminations \| Industrial Materials \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	25
2013 Rationalization Initiatives \| Contract Terminations \| Engineered Solutions \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	0
2013 Rationalization Initiatives \| Contract Terminations \| Corporate, R&D and Other \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Contract terminations	0
2014 Engineered Solutions Rationalization
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	465
2014 Engineered Solutions Rationalization \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Inventory loss	434
Fixed asset write-offs and other	(3)
2014 Engineered Solutions Rationalization \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	(16)
Contract terminations	50
2014 Corporate and Research & Development Rationalization \| Industrial Materials
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	(34)
2014 Corporate and Research & Development Rationalization \| Industrial Materials \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	0
2014 Corporate and Research & Development Rationalization \| Industrial Materials \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	0
2014 Corporate and Research & Development Rationalization \| Corporate, R&D and Other
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	1,687
2014 Corporate and Research & Development Rationalization \| Corporate, R&D and Other \| Research and Development
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	621
2014 Corporate and Research & Development Rationalization \| Corporate, R&D and Other \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	1,066
2014 Corporate and Research & Development Rationalization \| Employee Severance \| Industrial Materials \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	(34)
2014 Corporate and Research & Development Rationalization \| Employee Severance \| Corporate, R&D and Other \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	0
2015 Advanced Graphite Materials Rationalization
Restructuring Cost and Reserve [Line Items]
Total rationalization plan and related charges	2,649
2015 Advanced Graphite Materials Rationalization \| Cost of Sales
Restructuring Cost and Reserve [Line Items]
Inventory loss	369
Fixed asset write-offs and other	(105)
2015 Advanced Graphite Materials Rationalization \| Selling and Administrative
Restructuring Cost and Reserve [Line Items]
Other	3
2015 Advanced Graphite Materials Rationalization \| Employee Severance \| Rationalizations
Restructuring Cost and Reserve [Line Items]
Severance and related costs	$ 2,382

Rationalizations and Impairments (Rationalization Costs Incurred) (Details) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 31, 2015

Mar. 31, 2014

Rationalization Plan

Restructuring Cost and Reserve [Line Items]

Total rationalization plan and related charges

$ 6,503

$ 17,855

Rationalization Plan | Cost of Sales

Restructuring Cost and Reserve [Line Items]

Accelerated depreciation