Asset Sales and Other Accruals (Tables)

12 Months Ended

Dec. 31, 2012

Asset Sales and Other Accruals [Abstract]

Asset Sales and Other Accruals

			Years Ended December 31,
			2012		2011		2010
			(Millions)
Williams Partners
	Project feasibility costs		$	21	$	10	$	8
	Capitalization of project feasibility costs previously expensed			(19)		(11)		(1)
	Gains on sales of certain assets			(6)		-		(12)
	Involuntary conversion gains			-		(3)		(18)
	Accrual of regulatory liability related to overcollection of certain employee
		expenses		4		9		10
Williams NGL & Petchem Services
	Gulf Liquids litigation contingency accrual reduction (see Note 17)			-		(19)		-