Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share Table [Line Items]
Net income (loss) attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share	$ 373	$ (65)
Basic weighted-average shares	824,548	750,332
Effect of dilutive securities:
Diluted weighted-average shares	826,476	750,332
Earnings (loss) per common share:
Basic	$ 0.45	$ (0.09)
Diluted	$ 0.45	$ (0.09)
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,305	0
Stock Options [Member]
Effect of dilutive securities:
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	623	0