Subsequent Event Subsequent Event	12 Months Ended
Dec. 31, 2020
Subsequent Event [Abstract]
Subsequent Event	SUBSEQUENT EVENTSSubsequent to December 31, 2020, we acquired two companies, each for an immaterial amount. One company provides mechanical services within the Southern region of the United States, and the results of its operations will be included in our United States mechanical construction and facilities services segment. The other company provides electrical construction and maintenance services for a broad array of customers in the Midwestern region of the United States, and the results of its operations will be included in our United States electrical construction and facilities services segment. The acquisition of these businesses will be accounted for by the acquisition method, and the amounts paid will be allocated to their respective assets and liabilities, based upon the estimated fair value of such assets and liabilities at the respective date of acquisition by us.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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