Restructuring - Additional Information (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 27, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) employee	Dec. 31, 2019 USD ($) employee	Dec. 31, 2018 employee
Restructuring Cost and Reserve [Line Items]
Goodwill impairment charges	$ 9,100	$ 0	$ 9,053	$ 11,560
Asset impairment charges		0	10,472	14,141
Property, plant and equipment held for sale			200
Restructuring reserve, accrual adjustment		400
Restructuring (income) expense		(438)	11,237	785
Precision Optics
Restructuring Cost and Reserve [Line Items]
Goodwill impairment charges		0	9,053
Asset impairment charges			1,400
Restructuring (income) expense		(438)	2,052	$ 328
Severance costs			$ 400
Number of positions eliminated | employee			28
Number of positions eliminated | employee				19
Precision Optics | LAC Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring (income) expense			$ 1,700
Severance costs			$ 700
Number of positions eliminated | employee			20
Other restructuring costs			$ 1,000
Remaining severance payments			600
Remaining facility costs			1,000
Performance Alloys and Composites
Restructuring Cost and Reserve [Line Items]
Goodwill impairment charges		0	0
Restructuring (income) expense		0	8,763	$ 0
Severance costs			$ 2,100
Number of positions eliminated | employee			63
Other restructuring costs			$ 5,300
Remaining severance payments			500
Remaining facility costs			500
Other
Restructuring Cost and Reserve [Line Items]
Restructuring (income) expense		0	422	$ 457
Number of positions eliminated | employee				7
Advanced Materials
Restructuring Cost and Reserve [Line Items]
Goodwill impairment charges		0	0
Restructuring (income) expense		$ 0	$ 0	$ 0
Number of positions eliminated | employee					40