Earnings (Loss) Per Common Share from Continuing Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings (loss) per common share from continuing operations
Income (loss) from continuing operations attributable to The Williams Companies, Inc. available to common stockholders for basic and diluted earnings (loss) per common share	$ (40)		$ 1,678	$ 144	$ 1,917
Basic weighted-average shares	749,824		747,412	749,059	709,809
Diluted weighted-average shares	749,824	[1]	752,064	752,621	714,119
Earnings (loss) per common share from continuing operations:
Basic	$ (0.05)		$ 2.24	$ 0.19	$ 2.70
Diluted	$ (0.05)		$ 2.22	$ 0.19	$ 2.68
Nonvested restricted stock units [Member]
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements under effects of dilutive securities item	0		2,424	1,900	2,205
Earnings (loss) per common share from continuing operations (Textuals) [Abstract]
Number of weighted-average shares excluded from computation of diluted earnings per common share	1,700
Stock options [Member]
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements under effects of dilutive securities item	0		2,210	1,662	2,087
Earnings (loss) per common share from continuing operations (Textuals) [Abstract]
Number of weighted-average shares excluded from computation of diluted earnings per common share	1,500
Convertible debentures [Member]
Effect of dilutive securities:
Incremental dilutive shares, Convertible debt	0		18	0	18

[1] For the three months ended September 30, 2015, 1.7 million weighted-average nonvested restricted stock units and 1.5 million weighted-average stock options have been excluded from the computation of diluted earnings per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.