GOODWILL AND INTANGIBLE ASSETS - Goodwill (Details) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 8,108
Goodwill resulting from the acquisition of MYR	226
Ending balance	$ 8,334

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://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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