Debt and Banking Arrangements Long-Term Debt Issuances and Retirements (Details 1) - USD ($) $ in Millions	Jul. 06, 2017	Jul. 03, 2017	Apr. 15, 2017	Feb. 23, 2017	Feb. 01, 2017	Jun. 05, 2017	Apr. 03, 2017
Variable Interest Term Loan due 2018 [Member] | Williams Partners L.P. [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt retired	$ 850
3.75% Senior Notes Due 2027 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt face amount						$ 1,450
Long-term debt interest rate						3.75%
4.875% Senior Unsecured Notes due 2023 [Member] | Williams Partners L.P. [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt interest rate		4.875%
Long-term debt retired		$ 1,400
6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate				6.125%
Long-term debt retired				$ 750
4% Senior Unsecured Notes Due 2027 [Member] | Northwest Pipeline LLC [Member]
Debt Instrument [Line Items]
Long-term debt face amount							$ 250
Long-term debt interest rate							4.00%
Additional interest rate accrued for default of registration rights agreements first period							0.25%
Additional interest rate accrued for default of registration rights agreements each subsequent period							0.25%
Maximum additional interest rate accrued for default of registration rights agreements all periods							0.50%
5.95% Senior Unsecured Notes due 2017 [Member] | Northwest Pipeline LLC [Member]
Debt Instrument [Line Items]
Long-term debt interest rate			5.95%
Long-term debt retired			$ 185
7.25% Senior Unsecured Notes due 2017 [Member] | Williams Partners L.P. [Member]
Debt Instrument [Line Items]
Long-term debt interest rate					7.25%
Long-term debt retired					$ 600