Segment Reporting (Details 1) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 26, 2020	Jun. 28, 2019	Jun. 26, 2020	Jun. 28, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 271,468,000	$ 297,843,000	$ 549,414,000	$ 599,284,000
Semiconductor
Disaggregation of Revenue [Line Items]
Net sales	125,677,000	103,030,000	247,413,000	210,198,000
Consumer Electronics
Disaggregation of Revenue [Line Items]
Net sales	13,381,000	27,593,000	31,735,000	44,839,000
Industrial Components
Disaggregation of Revenue [Line Items]
Net sales	34,824,000	40,131,000	69,623,000	78,639,000
Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	23,721,000	31,921,000	44,463,000	65,360,000
Energy
Disaggregation of Revenue [Line Items]
Net sales	14,917,000	27,330,000	43,814,000	60,621,000
Telecomm and Data Center
Disaggregation of Revenue [Line Items]
Net sales	13,374,000	18,957,000	24,233,000	36,750,000
Automotive
Disaggregation of Revenue [Line Items]
Net sales	17,608,000	18,598,000	37,869,000	40,887,000
Other End Market
Disaggregation of Revenue [Line Items]
Net sales	27,966,000	30,283,000	50,264,000	61,990,000
Performance Alloys and Composites
Disaggregation of Revenue [Line Items]
Net sales	101,614,000	135,231,000	200,681,000	262,344,000
Performance Alloys and Composites | Semiconductor
Disaggregation of Revenue [Line Items]
Net sales	1,537,000	1,303,000	2,443,000	3,268,000
Performance Alloys and Composites | Consumer Electronics
Disaggregation of Revenue [Line Items]
Net sales	9,956,000	22,663,000	24,651,000	36,218,000
Performance Alloys and Composites | Industrial Components
Disaggregation of Revenue [Line Items]
Net sales	23,831,000	28,585,000	47,171,000	55,015,000
Performance Alloys and Composites | Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	17,952,000	26,046,000	32,158,000	53,120,000
Performance Alloys and Composites | Energy
Disaggregation of Revenue [Line Items]
Net sales	5,590,000	11,303,000	11,019,000	22,397,000
Performance Alloys and Composites | Telecomm and Data Center
Disaggregation of Revenue [Line Items]
Net sales	12,586,000	18,244,000	22,575,000	35,836,000
Performance Alloys and Composites | Automotive
Disaggregation of Revenue [Line Items]
Net sales	16,415,000	16,564,000	34,579,000	37,277,000
Performance Alloys and Composites | Other End Market
Disaggregation of Revenue [Line Items]
Net sales	13,747,000	10,523,000	26,085,000	19,213,000
Advanced Materials
Disaggregation of Revenue [Line Items]
Net sales	150,108,000	133,238,000	310,273,000	277,263,000
Advanced Materials | Semiconductor
Disaggregation of Revenue [Line Items]
Net sales	123,908,000	101,634,000	244,727,000	206,725,000
Advanced Materials | Consumer Electronics
Disaggregation of Revenue [Line Items]
Net sales	21,000	500,000	138,000	705,000
Advanced Materials | Industrial Components
Disaggregation of Revenue [Line Items]
Net sales	8,419,000	7,704,000	16,781,000	15,632,000
Advanced Materials | Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	1,650,000	1,125,000	3,077,000	2,618,000
Advanced Materials | Energy
Disaggregation of Revenue [Line Items]
Net sales	9,327,000	16,027,000	32,795,000	38,224,000
Advanced Materials | Telecomm and Data Center
Disaggregation of Revenue [Line Items]
Net sales	788,000	713,000	1,658,000	914,000
Advanced Materials | Automotive
Disaggregation of Revenue [Line Items]
Net sales	1,186,000	1,669,000	3,266,000	3,023,000
Advanced Materials | Other End Market
Disaggregation of Revenue [Line Items]
Net sales	4,809,000	3,866,000	7,831,000	9,422,000
Precision Coatings
Disaggregation of Revenue [Line Items]
Net sales	19,746,000	29,374,000	38,460,000	59,677,000
Precision Coatings | Semiconductor
Disaggregation of Revenue [Line Items]
Net sales	232,000	93,000	243,000	205,000
Precision Coatings | Consumer Electronics
Disaggregation of Revenue [Line Items]
Net sales	3,404,000	4,430,000	6,946,000	7,916,000
Precision Coatings | Industrial Components
Disaggregation of Revenue [Line Items]
Net sales	2,574,000	3,842,000	5,671,000	7,992,000
Precision Coatings | Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	4,119,000	4,750,000	9,228,000	9,622,000
Precision Coatings | Energy
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Precision Coatings | Telecomm and Data Center
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Precision Coatings | Automotive
Disaggregation of Revenue [Line Items]
Net sales	7,000	365,000	24,000	587,000
Precision Coatings | Other End Market
Disaggregation of Revenue [Line Items]
Net sales	9,410,000	15,894,000	16,348,000	33,355,000
Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Semiconductor
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Consumer Electronics
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Industrial Components
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Energy
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Telecomm and Data Center
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Automotive
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Other End Market
Disaggregation of Revenue [Line Items]
Net sales	$ 0	$ 0	$ 0	$ 0