Acquisitions and Divestitures Acquisitions (Tables)

12 Months Ended

Dec. 31, 2020

Business Acquisition [Line Items]

Schedule of Business Acquisitions, by Acquisition [Table Text Block]

The following table presents the allocation of the acquisition date fair value of the major classes of the assets acquired, which are presented in the Northeast G&P segment, and liabilities assumed, including post closing purchase price adjustments. The net assets acquired reflect the sum of the consideration transferred and the noncash elimination of the fair value of our existing equity-method investment upon our acquisition of the additional interest. The fair value of accounts receivable acquired, presented in current assets in the table, equals contractual amounts receivable.

	(Millions)
Current assets, including $13 million cash acquired	$	56
Property, plant, and equipment	1,387
Other intangible assets	328
Total identifiable assets acquired	1,771
Current liabilities	7
Total liabilities assumed	7
Net identifiable assets acquired	1,764
Goodwill	187
Net assets acquired	$	1,951

Business Acquisition, Pro Forma Information [Table Text Block]

The following unaudited pro forma Revenues and Net income (loss) attributable to The Williams Companies, Inc. for the years ended December 31, 2019 and 2018, respectively, are presented as if the UEOM acquisition had been completed on January 1, 2018. These pro forma amounts are not necessarily indicative of what the actual results would have been if the acquisition had in fact occurred on the date or for the periods indicated, nor do they purport to project Revenues or Net income (loss) attributable to The Williams Companies, Inc. for any future periods or as of any date. These amounts do not give effect to any potential cost savings, operating synergies, or revenue enhancements to result from the transaction or the potential costs to achieve these cost savings, operating synergies, and revenue enhancements.

	Year Ended December 31,
	2019		2018
	(Millions)
Revenues	$	8,233	$	8,836
Net income (loss) attributable to The Williams Companies, Inc.	928		(128)