Rationalizations and Impairments (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended	3 Months Ended		12 Months Ended	0 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Sep. 30, 2014	Dec. 31, 2015	Mar. 02, 2015 employee
2013 Rationalization Initiatives
Restructuring Cost and Reserve [Line Items]
Expected cash outlay	$ 549,000	$ 16,494,000
Industrial Materials Segment
Restructuring Cost and Reserve [Line Items]
Estimated reduction in capacity (metric tons)	60,000
Expected number of positions eliminated (employees)	600
Number of positions eliminated (percent)			20.00%
Engineered Solutions Segment
Restructuring Cost and Reserve [Line Items]
Expected number of positions eliminated (employees)	40
2014 Engineered Solutions Rationalization
Restructuring Cost and Reserve [Line Items]
Expected cash outlay	434,000	916,000
2014 Corporate and Research & Development Rationalization
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated (percent)				25.00%
Expected cost				20,000,000
Expected cash outlay	2,231,000	1,155,000
2014 Corporate and Research & Development Rationalization | Scenario, Plan
Restructuring Cost and Reserve [Line Items]
Expected cash outlay					12,000,000
2015 Advanced Graphite Materials Rationalization
Restructuring Cost and Reserve [Line Items]
Expected number of positions eliminated (employees)						85
Expected cost						10,000,000
Expected cash outlay	17,000
2015 Advanced Graphite Materials Rationalization | Scenario, Plan
Restructuring Cost and Reserve [Line Items]
Expected cash outlay					$ 8,000,000