Long-Term Debt (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Nov. 15, 2013	Mar. 04, 2014	Jun. 27, 2014	Jun. 24, 2014
Long-term Debt
Capital lease obligations	$ 5		$ 1
Net unamortized debt premium (discount)	187	[1]	(37)	[1]
Total long-term debt, including current portion	20,892		11,354
Long-term debt due within one year	(4)		(1)
Long-term debt	20,888		11,353
Transcontinental Gas Pipe Line Company, LLC [Member] | 6.4% Senior Unsecured Notes due 2016 [Member]
Long-term Debt
Long-term debt	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%
Williams Partners L.P. [Member]
Long-term Debt
Credit facility loans	0
Williams Partners L.P. [Member] | 3.8% Senior Unsecured Notes due 2015 [Member]
Long-term Debt
Long-term debt	750	[2]	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] | 3.35% 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] | 4.5% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt	600		600
Long-term debt interest rate	4.50%				4.50%
Williams Partners L.P. [Member] | 4.3% Senior Unsecured Notes Due 2024 [Member]
Long-term Debt
Long-term debt	1,000		0
Long-term debt interest rate	4.30%					4.30%
Williams Partners L.P. [Member] | 3.9% Senior Unsecured Notes due 2025 [Member]
Long-term Debt
Long-term debt	750		0
Long-term debt interest rate	3.90%						3.90%
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%				5.80%
Williams Partners L.P. [Member] | 5.4% Senior Unsecured Notes Due 2044 [Member]
Long-term Debt
Long-term debt	500		0
Long-term debt interest rate	5.40%					5.40%
Williams Partners L.P. [Member] | 4.9% Senior Unsecured Notes due 2045 [Member]
Long-term Debt
Long-term debt	500		0
Long-term debt interest rate	4.90%						4.90%
The Williams Companies, Inc. [Member]
Long-term Debt
Credit facility loans	370		0
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		0
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		0
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%
Access Midstream Partners L.P. [Member]
Long-term Debt
Credit facility loans	640	[3]	0	[3]
Access Midstream Partners L.P. [Member] | 5.875% Senior Unsecured Notes due 2021 [Member]
Long-term Debt
Long-term debt	750	[3]	0	[3]
Long-term debt interest rate	5.875%
Access Midstream Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member]
Long-term Debt
Long-term debt	750	[3]	0	[3]
Long-term debt interest rate	6.125%
Access Midstream Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2023 [Member]
Long-term Debt
Long-term debt	1,400	[3]	0	[3]
Long-term debt interest rate	4.875%
Access Midstream Partners L.P. [Member] | 4.875% Senior Unsecured Notes due 2024 [Member]
Long-term Debt
Long-term debt	$ 750	[3]	$ 0	[3]
Long-term debt interest rate	4.875%

[1] Includes premium related to the fair value of ACMP debt. See Note 2 – Acquisitions.

[2] Presented as long-term debt due to the merged partnership’s intent and ability to refinance.

[3] See Note 2 – Acquisitions.