Long-Term Debt (Details) - USD ($) $ in Millions		Dec. 31, 2015	Apr. 15, 2015	Mar. 03, 2015	Dec. 31, 2014	Jun. 24, 2014
Long-term Debt
Capital lease obligations		$ 1			$ 5
Debt issuance costs		(123)			(108)
Net unamortized debt premium (discount)		110			187
Total long-term debt, including current portion		23,988			20,784
Long-term debt due within one year		(176)			(4)
Long-term Debt and Capital Lease Obligations		23,812			20,780
Transcontinental Gas Pipe Line Company, LLC [Member] | 6.4% Senior Unsecured Notes due 2016 [Member]
Long-term Debt
Long-term debt	[1]	$ 200			200
Long-term debt interest rate		6.40%
Transcontinental Gas Pipe Line Company, LLC [Member] | 6.05% Senior Unsecured Notes due 2018 [Member]
Long-term Debt
Long-term debt		$ 250			250
Long-term debt interest rate		6.05%
Transcontinental Gas Pipe Line Company, LLC [Member] | 7.08% Debentures due 2026 [Member]
Long-term Debt
Long-term debt		$ 8			8
Long-term debt interest rate		7.08%
Transcontinental Gas Pipe Line Company, LLC [Member] | 7.25% Debentures due 2026 [Member]
Long-term Debt
Long-term debt		$ 200			200
Long-term debt interest rate		7.25%
Transcontinental Gas Pipe Line Company, LLC [Member] | 5.4% Senior Unsecured Notes due 2041 [Member]
Long-term Debt
Long-term debt		$ 375			375
Long-term debt interest rate		5.40%
Transcontinental Gas Pipe Line Company, LLC [Member] | 4.45% Senior Unsecured Notes due 2042 [Member]
Long-term Debt
Long-term debt		$ 400			400
Long-term debt interest rate		4.45%
Northwest Pipeline LLC [Member] | 7% Senior Unsecured Notes due 2016 [Member]
Long-term Debt
Long-term debt		$ 175			175
Long-term debt interest rate		7.00%
Northwest Pipeline LLC [Member] | 5.95% Senior Unsecured Notes due 2017 [Member]
Long-term Debt
Long-term debt		$ 185			185
Long-term debt interest rate		5.95%
Northwest Pipeline LLC [Member] | 6.05% Senior Unsecured Notes due 2018 [Member]
Long-term Debt
Long-term debt		$ 250			250
Long-term debt interest rate		6.05%
Northwest Pipeline LLC [Member] | 7.125% Debentures due 2025 [Member]
Long-term Debt
Long-term debt		$ 85			85
Long-term debt interest rate		7.125%
The Williams Companies, Inc. [Member]
Long-term Debt
Credit facility loans		$ 650			370
The Williams Companies, Inc. [Member] | 7.875% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt		$ 371			371
Long-term debt interest rate		7.875%
The Williams Companies, Inc. [Member] | 3.7% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt		$ 850			850
Long-term debt interest rate		3.70%
The Williams Companies, Inc. [Member] | 4.55% Senior Unsecured Notes due 2024 [Member]
Long-term Debt
Long-term debt		$ 1,250			1,250
Long-term debt interest rate		4.55%				4.55%
The Williams Companies, Inc. [Member] | 7.5% Debentures due 2031 [Member]
Long-term Debt
Long-term debt		$ 339			339
Long-term debt interest rate		7.50%
The Williams Companies, Inc. [Member] | 7.75% Senior Unsecured Notes due 2031 [Member]
Long-term Debt
Long-term debt		$ 252			252
Long-term debt interest rate		7.75%
The Williams Companies, Inc. [Member] | 8.75% Senior Unsecured Notes due 2032 [Member]
Long-term Debt
Long-term debt		$ 445			445
Long-term debt interest rate		8.75%
The Williams Companies, Inc. [Member] | 5.75% Senior Unsecured Notes due 2044 [Member]
Long-term Debt
Long-term debt		$ 650			650
Long-term debt interest rate		5.75%				5.75%
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 [Member]
Long-term Debt
Long-term debt		$ 55			55
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 Minimum Interest Rate [Member]
Long-term Debt
Long-term debt interest rate		5.50%
The Williams Companies, Inc. [Member] | Various - 5.5% to 10.25% Senior Unsecured Notes and Debentures due 2019 to 2033 Maximum Interest Rate [Member]
Long-term Debt
Long-term debt interest rate		10.25%
Williams Partners L.P. [Member]
Long-term Debt
Credit facility loans		$ 1,310			640
Williams Partners L.P. [Member] | 3.8% Senior Unsecured Notes due 2015 [Member]
Long-term Debt
Long-term debt	[2]	$ 0			750
Long-term debt interest rate		3.80%
Williams Partners L.P. [Member] | 7.25% Senior Unsecured Notes due 2017 [Member]
Long-term Debt
Long-term debt		$ 600			600
Long-term debt interest rate		7.25%
Williams Partners L.P. [Member] | 5.25% Senior Unsecured Notes due 2020 [Member]
Long-term Debt
Long-term debt		$ 1,500			1,500
Long-term debt interest rate		5.25%
Williams Partners L.P. [Member] | 4.125% Senior Unsecured Notes due 2020 [Member]
Long-term Debt
Long-term debt		$ 600			600
Long-term debt interest rate		4.125%
Williams Partners L.P. [Member] | 4% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt		$ 500			500
Long-term debt interest rate		4.00%
Williams Partners L.P. [Member] | 3.6% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt		$ 1,250			0
Long-term debt interest rate		3.60%		3.60%
Williams Partners L.P. [Member] | 5.875% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt		$ 0			750
Long-term debt interest rate		5.875%	5.875%
Williams Partners L.P. [Member] | 3.35% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt		$ 750			750
Long-term debt interest rate		3.35%
Williams Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt		$ 750			750
Long-term debt interest rate		6.125%
Williams Partners L.P. [Member] | 4.5% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt		$ 600			600
Long-term debt interest rate		4.50%
Williams Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt		$ 1,400			1,400
Long-term debt interest rate		4.875%
Williams Partners L.P. [Member] | 4.3% Senior Unsecured Notes Due 2024 [Member]
Long-term Debt
Long-term debt		$ 1,000			1,000
Long-term debt interest rate		4.30%
Williams Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2024 [Member]
Long-term Debt
Long-term debt		$ 750			750
Long-term debt interest rate		4.875%
Williams Partners L.P. [Member] | 3.9% Senior Unsecured Notes due 2025 [Member]
Long-term Debt
Long-term debt		$ 750			750
Long-term debt interest rate		3.90%
Williams Partners L.P. [Member] | 4% Senior Unsecured Notes due 2025 [Member]
Long-term Debt
Long-term debt		$ 750			0
Long-term debt interest rate		4.00%		4.00%
Williams Partners L.P. [Member] | 6.3% Senior Unsecured Notes due 2040 [Member]
Long-term Debt
Long-term debt		$ 1,250			1,250
Long-term debt interest rate		6.30%
Williams Partners L.P. [Member] | 5.8% Senior Unsecured Notes due 2043 [Member]
Long-term Debt
Long-term debt		$ 400			400
Long-term debt interest rate		5.80%
Williams Partners L.P. [Member] | 5.4% Senior Unsecured Notes Due 2044 [Member]
Long-term Debt
Long-term debt		$ 500			500
Long-term debt interest rate		5.40%
Williams Partners L.P. [Member] | 4.9% Senior Unsecured Notes due 2045 [Member]
Long-term Debt
Long-term debt		$ 500			500
Long-term debt interest rate		4.90%
Williams Partners L.P. [Member] | 5.1% Senior Unsecured Notes due 2045 [Member]
Long-term Debt
Long-term debt		$ 1,000			0
Long-term debt interest rate		5.10%		5.10%
Williams Partners L.P. [Member] | Variable Interest Term Loan due 2018 [Member]
Long-term Debt
Long-term debt		$ 850			$ 0

[1] Presented as long-term debt at December 31, 2015, due to Transco’s intent and ability to refinance.

[2] Presented as long-term debt at December 31, 2014, due to WPZ's intent and ability to refinance.