Asset Sales and Other Accruals (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component of Other Expense, Nonoperating [Line Items]
Operating and maintenance expenses	$ 1,027	$ 990	$ 870
Early debt retirement costs	0	271	606
Williams NGL & Petchem Services [Member] | Gulf Liquids [Member]
Component of Other Expense, Nonoperating [Line Items]
Gulf Liquids interest expense reduction associated wtih litigation contingency acrual reversal		14
Charges Related To Leak At Underground Natural Gas Storage Facility [Member] | Williams Partners [Member]
Component of Other Expense, Nonoperating [Line Items]
Operating and maintenance expenses	2	15	5
Corporate Realignment [Member]
Component of Other Expense, Nonoperating [Line Items]
Other transaction costs	26
Strategic Restructuring [Member]
Component of Other Expense, Nonoperating [Line Items]
Other transaction costs			45
Noncontrolling Interests | Strategic Restructuring [Member]
Component of Other Expense, Nonoperating [Line Items]
Other transaction costs			$ 7