Schedule I Condensed Financial Information Of Registrant (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
	Jun. 23, 2014	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Condensed Statement Of Comprehensive Income Parent Company Only [Abstract]
Equity earnings (losses)		$ 335		$ 144	$ 134
Interest incurred - external		(1,118)		(888)	(611)
Gain on remeasurement of equity-method investment		0		2,544	0
Other income (expense) – net		102		31	0
Income (loss) from continuing operations before income taxes		(1,713)		3,584	1,080
Provision (benefit) for income taxes		(399)		1,249	401
Income (loss) from continuing operations		(571)		2,110	441
Income (loss) from discontinued operations		0		4	(11)
Net income (loss) attributable to The Williams Companies, Inc.		$ (571)		$ 2,114	$ 430
Basic earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.76)		$ 2.93	$ 0.65
Income (loss) from discontinued operations		0.00		0.01	(0.02)
Net income (loss)		$ (0.76)		$ 2.94	$ 0.63
Weighted-average shares (thousands)		749,271		719,325	682,948
Diluted earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.76)		$ 2.91	$ 0.64
Income (loss) from discontinued operations		0.00		0.01	(0.02)
Net income (loss)		$ (0.76)		$ 2.92	$ 0.62
Weighted-average shares (thousands)		749,271	[1]	723,641	687,185
Other comprehensive income (loss):
Other comprehensive income (loss)		$ (171)		$ (176)	$ 198
Comprehensive Income (loss) attributable to The Williams Companies, Inc.		(672)		1,957	628
Assets, Current [Abstract]
Cash and cash equivalents		240		681	839	$ 100	$ 240
Other current assets and deferred charges						217	213
Total current assets						1,527	1,890
Property, plant, and equipment – net						29,579	28,081
Other noncurrent assets						561	511
Total assets						49,020	50,455
Liabilities, Current [Abstract]
Accounts payable						744	865
Total current liabilities						2,497	2,567
Long-term debt						23,812	20,780
Deferred income taxes						$ 4,218	$ 4,712
Contingent liabilities and commitments
Equity: [Abstract]
Common stock						$ 784	$ 782
Total stockholders’ equity						6,148	8,777
Total liabilities and stockholders' equity						49,020	50,455
Condensed Statement Of Cash Flows Parent Company Only [Abstract]
Net Cash Provided (Used) by Operating Activities		2,678		2,115	2,217
FINANCING ACTIVITIES:
Proceeds from long-term debt		9,772		7,321	2,699
Payments of long-term debt		(6,516)		(1,828)	(2,081)
Proceeds from issuance of common stock	$ 3,378	27		3,416	18
Dividends paid		(1,836)		(1,412)	(982)
Other – net		(1)		17	17
Net cash provided (used) by financing activities		481		7,601	1,677
INVESTING ACTIVITIES:
Capital expenditures		(3,336)		(20,756)	(3,731)
Other – net		572		280	(22)
Net cash provided (used) by investing activities		(3,299)		(10,157)	(4,052)
Increase (decrease) in cash and cash equivalents		(140)		(441)	(158)
Cash and cash equivalents at beginning of year		240		681	839
Cash and cash equivalents at end of year		100		240	681
Parent Company [Member]
Condensed Statement Of Comprehensive Income Parent Company Only [Abstract]
Equity in earnings of consolidated subsidiaries		232		1,799	1,564
Equity earnings (losses)		0		(7)	30
Interest incurred - external		(255)		(206)	(156)
Interest incurred - affiliate		(828)		(797)	(722)
Interest income - affiliate		6		10	71
Gain on remeasurement of equity-method investment		0		2,544	0
Other income (expense) – net		(75)		(13)	32
Income (loss) from continuing operations before income taxes		(920)		3,330	819
Provision (benefit) for income taxes		(349)		1,220	378
Income (loss) from continuing operations		(571)		2,110	441
Income (loss) from discontinued operations		0		4	(11)
Net income (loss) attributable to The Williams Companies, Inc.		$ (571)		$ 2,114	$ 430
Basic earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.76)		$ 2.93	$ 0.65
Income (loss) from discontinued operations		0.00		0.01	(0.02)
Net income (loss)		$ (0.76)		$ 2.94	$ 0.63
Weighted-average shares (thousands)		749,271		719,325	682,948
Diluted earnings (loss) per common share:
Income (loss) from continuing operations		$ (0.76)		$ 2.91	$ 0.64
Income (loss) from discontinued operations		0.00		0.01	(0.02)
Net income (loss)		$ (0.76)		$ 2.92	$ 0.62
Weighted-average shares (thousands)		749,271		723,641	687,185
Other comprehensive income (loss):
Equity in other comprehensive income (loss) of consolidated subsidiaries		$ (204)		$ (96)	$ (41)
Other comprehensive income (loss) attributable to The Williams Companies, Inc.		33		(80)	239
Other comprehensive income (loss)		(171)		(176)	198
Other comprehensive income (loss) attributable to noncontrolling interests		(70)		(19)	0
Comprehensive Income (loss) attributable to The Williams Companies, Inc.		(672)		1,957	628
Assets, Current [Abstract]
Cash and cash equivalents		49		282	340	12	49
Other current assets and deferred charges						62	246
Total current assets						74	295
Investments in and advances to consolidated subsidiaries						30,927	31,405
Property, plant, and equipment – net						99	99
Other noncurrent assets						12	12
Total assets						31,112	31,811
Liabilities, Current [Abstract]
Accounts payable						27	27
Other current liabilities						163	174
Total current liabilities						190	201
Long-term debt						4,811	4,528
Notes payable - affiliates						15,506	13,295
Pension, other postretirement and other noncurrent liabilities						336	409
Deferred income taxes						$ 4,121	$ 4,601
Contingent liabilities and commitments
Equity: [Abstract]
Common stock						$ 784	$ 782
Other stockholders' equity						5,364	7,995
Total stockholders’ equity						6,148	8,777
Total liabilities and stockholders' equity						31,112	$ 31,811
Condensed Statement Of Cash Flows Parent Company Only [Abstract]
Net Cash Provided (Used) by Operating Activities		(1,209)		(500)	19
FINANCING ACTIVITIES:
Proceeds from long-term debt		2,097		2,935	0
Payments of long-term debt		(1,817)		(671)	(1)
Changes in notes payable to affiliates		2,211		2,465	1,892
Tax benefit of stock-based awards		0		25	19
Proceeds from issuance of common stock		27		3,416	18
Dividends paid		(1,836)		(1,412)	(982)
Other – net		(2)		(17)	(3)
Net cash provided (used) by financing activities		680		6,741	943
INVESTING ACTIVITIES:
Capital expenditures		(29)		(54)	(23)
Purchase of Access Midstream Partners		0		(5,995)	0
Changes in investments in and advances to consolidated subsidiaries		521		(450)	(985)
Other – net		0		25	(12)
Net cash provided (used) by investing activities		492		(6,474)	(1,020)
Increase (decrease) in cash and cash equivalents		(37)		(233)	(58)
Cash and cash equivalents at beginning of year		49		282	340
Cash and cash equivalents at end of year		12		49	282
Guarantees [Abstract]
Guarantor Obligations, Maximum Exposure, Undiscounted						$ 631
Cash Dividends Received [Abstract]
Proceeds from Dividends Received		$ 1,800		$ 1,900	$ 1,500

[1] For the year ended December 31, 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 (loss) per common share as their inclusion would be antidilutive due to our loss from continuing operations attributable to The Williams Companies, Inc.