Revenue - Disaggregation of Revenue and Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total	$ 98,947	$ 100,171
United States
Disaggregation of Revenue [Line Items]
Total	74,410	89,595
North America (outside of United States)
Disaggregation of Revenue [Line Items]
Total	3,411	2,320
Pacific Rim
Disaggregation of Revenue [Line Items]
Total	13,841	5,528
Europe
Disaggregation of Revenue [Line Items]
Total	3,122	1,610
Other
Disaggregation of Revenue [Line Items]
Total	4,163	1,118
Power Systems
Disaggregation of Revenue [Line Items]
Total	38,230	25,159
Industrial
Disaggregation of Revenue [Line Items]
Total	45,803	34,320
Transportation
Disaggregation of Revenue [Line Items]
Total	$ 14,914	$ 40,692