Debt and Banking Arrangements Credit Facilities and Commercial Paper (Details 2) - Williams Companies Inc [Member] $ in Millions	Mar. 31, 2020 USD ($)
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	$ 4,500	[1]
Credit facility, loans outstanding	1,700	[1]
Commercial Paper [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	4,000
Commercial paper, outstanding	0
Letters Of Credit Under Certain Bilateral Bank Agreements [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding	$ 14

[1] In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.