Revenue Recognition - Summary of Disaggregated Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 123,018	$ 113,777	$ 84,197	$ 103,075	$ 115,040	$ 115,651	$ 120,684	$ 117,625	$ 424,066	$ 468,999	$ 470,483
Transportation
Disaggregation of Revenue [Line Items]
Revenues									241,445	299,005
Industrial
Disaggregation of Revenue [Line Items]
Revenues									92,784	78,369
Medical
Disaggregation of Revenue [Line Items]
Revenues									39,070	41,901
Aerospace and Defense
Disaggregation of Revenue [Line Items]
Revenues									39,327	32,569
Telecommunications & IT
Disaggregation of Revenue [Line Items]
Revenues									$ 11,440	$ 17,155