SUPPLEMENTAL FINANCIAL STATEMENT DATA - Carrying Value of Goodwill by Reporting Unit (Details) $ in Thousands	3 Months Ended
Apr. 03, 2020 USD ($)
Changes in carrying value of goodwill
Goodwill at beginning of period	$ 127,647
Additions/Adjustments	2,356
Goodwill at end of period	130,003
Energy
Changes in carrying value of goodwill
Goodwill at beginning of period	126,898
Additions/Adjustments	2,356
Goodwill at end of period	129,254
Engineering and Consulting
Changes in carrying value of goodwill
Goodwill at beginning of period	749
Goodwill at end of period	$ 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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 45
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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
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-Publisher FASB
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-Topic 350
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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