GOODWILL AND OTHER INTANGIBLE ASSETS - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Jan. 01, 2021
Changes in carrying value of goodwill
Goodwill at beginning of period	$ 130,124	$ 127,647
Additional Purchase Cost	0	0
Additions/Adjustments	0	2,477
Goodwill at end of period	130,124	130,124
Energy
Changes in carrying value of goodwill
Goodwill at beginning of period	129,375	126,898
Additional Purchase Cost	0	0
Additions/Adjustments	0	2,477
Goodwill at end of period	129,375	129,375
Engineering and Consulting
Changes in carrying value of goodwill
Goodwill at beginning of period	749	749
Additional Purchase Cost	0	0
Additions/Adjustments	0	0
Goodwill at end of period	$ 749	$ 749

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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