CHANGES IN BUSINESS - Discontinued Operation and Disposition (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	May 12, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Jul. 11, 2018
Liabilities:
Current liabilities of discontinued operations		$ 104		$ 104		$ 316
Long-term liabilities of discontinued operations		3,523		3,523		4,250
Income (loss) before income taxes
Interest expense, net		1,261	$ 1,213	2,480	$ 2,506
Income (loss) from discontinued operations before income tax		(47)	243	(47)	164
Income tax expense (benefit)		(640)	18	(623)	37
Income (loss) from discontinued operations		593	225	576	127
Discontinued operations, disposed of by means other than sale | Electrical Solutions | Pension
Liabilities:
Liability for pension obligation							$ 2,900
Decrease in liability for pension obligation	$ 300
Income (loss) before income taxes
Expected Periodic Payment	$ 300
Discontinued operations disposed of by sale
Income (loss) before income taxes
General and administrative expenses			6		34
Interest expense, net		30	(21)	30	30
Income (loss) from discontinued operations before income tax		(47)	243	(47)	164
Income tax expense (benefit)		(640)	18	(623)	37
Income (loss) from discontinued operations		593	225	576	127
Discontinued operations disposed of by sale | Electrical Solutions And Mechanical Solutions
Assets and liabilities
Assets of discontinued operations		0		0		0
Liabilities:
Current liabilities of discontinued operations		104		104		316
Liability for pension obligation		2,287		2,287		2,368
Liability for uncertain tax positions		1,236		1,236		1,882
Long-term liabilities of discontinued operations		3,523		3,523		4,250
Total liabilities of discontinued operations		3,627		3,627		$ 4,566
Discontinued operations disposed of by sale | Electrical Solutions
Income (loss) before income taxes
Loss (gain) on disposal - Electrical Solutions		$ 17	$ (228)	$ 17	$ (228)