Discontinued Operations - Net Sales and Losses from Discontinued Operations (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Sep. 04, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations before income taxes		$ 72	$ (13,478)	$ 72	$ (23,565)
Income tax benefit from discontinued operations		0	3,730	0	5,509
Income (loss) from discontinued operations		72	(9,748)	72	(18,056)
Test and Inspection Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations	$ (10,034)
Test and Inspection Services | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales		0	2,520	0	13,590
Income (loss) from discontinued operations before income taxes		72	(306)	72	(10,393)
Income tax benefit from discontinued operations		0	592	0	2,371
Loss on the sale of discontinued operations		0	(13,172)	0	(13,172)
Income tax benefit on the sale of discontinued operations		0	3,138	0	3,138
Income (loss) from discontinued operations		$ 72	$ (9,748)	$ 72	$ (18,056)