Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Regulatory liabilities	$ 323,032	$ 290,430
Salary and Wage, Excluding Cost of Good and Service Sold [Abstract]
Stock-based compensation expense	1,500	1,800	$ 1,900
Other Postretirement Benefit Costs
Defined Benefit Plan Disclosure [Line Items]
Regulatory liabilities	37,700	36,200
Williams Companies Inc [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension cost	2,200	3,900	5,200
Defined contribution plan matching contributions expense	1,800	1,900	2,100
Williams Companies Inc [Member] | Retiree health care and life insurance benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Regulatory liabilities	$ (1,500)	(2,100)	(3,500)
Williams Companies Inc [Member] | Pension Plan [Member] | Directly charged [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Payment for Settlement		1,300	3,000
Williams Companies Inc [Member] | Pension Plan [Member] | Allocated corporate expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Payment for Settlement		$ 700	$ 1,100