Asset Sales and Other Accruals (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		6 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2010	Mar. 31, 2011	Jun. 30, 2011 Williams Partners	Mar. 31, 2011 Other [Member]	Jun. 30, 2010 Other [Member]	Jun. 30, 2011 Exploration & Production [Member]	Jun. 30, 2010 Noncontrolling Interests
Component of Other Expense, Nonoperating [Line Items]
Payment received from equity method investment sold				$ 11	$ 13
Project feasibility costs reversed from expense to capital			10
Other Transaction Costs	41						5
Early debt retirement costs	606
Corrections charge for estimated annual compression service						14
Accelerated amortization of debt costs	$ 4
Number of quarterly payments		6