Financial Instruments, Derivatives, Guarantees and Concentration of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2010

Financial Instruments Derivatives Guarantees and Concentration of Credit Risk (Tables) [Abstract]

Carrying amounts and fair values of financial instruments

	December 31,
	2010						2009
	Carrying						Carrying
Asset (Liability)	Amount			Fair Value			Amount			Fair Value
	(Millions)
Cash and cash equivalents	$	795		$	795		$	1,867		$	1,867
Restricted cash (current and noncurrent)	$	28		$	28		$	28		$	28
ARO Trust Investments	$	40		$	40		$	22		$	22
Long-term debt, including current portion(a)	$	(9,104	)	$	(9,990	)	$	(8,273	)	$	(9,142	)
Guarantees	$	(35	)	$	(34	)	$	(36	)	$	(33	)
Other	$	(23	)	$	(25	)(b)	$	(23	)	$	(25	)(b)
Net energy derivatives:
Energy commodity cash flow hedges	$	266		$	266		$	178		$	178
Other energy derivatives	$	18		$	18		$	(90	)	$	(90	)

(a)	Excludes capital leases. (See Note 11.)
(b)	Excludes certain cost-based investments in companies that are not publicly traded and therefore it is not practicable to estimate fair value. The carrying value of these investments was $2 million at December 31, 2010 and December 31, 2009.

Notional quantities of the net long (short) positions in commodity derivatives portfolio

		Unit of	Central Hub			Basis			Index
Derivative Notional Volumes		Measure	Risk			Risk			Risk		Options
Designated as Hedging Instruments
Exploration & Production	Risk Management	MMBtu		(200,100,000	)		(200,100,000	)				(100,375,000	)
Not Designated as Hedging Instruments
Exploration & Production	Risk Management	MMBtu		(9,077,499	)		(20,195,000	)		16,586,059
Williams Partners	Risk Management	Gallons		(3,990,000	)
Exploration & Production	Other	MMBtu		150,400			(14,766,500	)

Fair value of energy commodity derivatives

	December 31,
	2010				2009
	Assets		Liabilities		Assets		Liabilities
	(Millions)
Designated as hedging instruments	$	288	$	22	$	352	$	174
Not designated as hedging instruments:
Legacy natural gas contracts from former power business		186		187		505		526
All other		99		80		237		306
Total derivatives not designated as hedging instruments		285		267		742		832
Total derivatives	$	573	$	289	$	1,094	$	1,006

Pre-tax gains and losses for energy commodity derivatives designated as cash flow hedges, as recognized in accumulated other comprehensive income (loss) (AOCI) or revenues

	Years Ended
	December 31,
	2010		2009		Classification
	(Millions)
Net gain recognized in other comprehensive income (loss) (effective portion)	$	495	$	262	AOCI
Net gain reclassified from accumulated other comprehensive income (loss) into income (effective portion)	$	342	$	618	Revenues or Costs and Operating Expenses
Gain recognized in income (ineffective portion)	$	9	$	4	Revenues or Costs and Operating Expenses

Pre-tax gains and losses for energy commodity derivatives not designated as hedging instruments

	Years Ended
	December 31,
	2010		2009
	(Millions)
Revenues	$	46	$	37
Costs and operating expenses		28		33
Net gain	$	18	$	4

Concentration of receivables, net of allowances, by product or service

	December 31,
	2010		2009
	(Millions)
Receivables by product or service:
Sale of natural gas and related products and services	$	635	$	599
Transportation of natural gas and related products		149		160
Joint interest		71		56
Other		4		1
Total	$	859	$	816

Gross credit exposure from derivative contracts

	Investment
Counterparty Type	Grade(a)		Total
	(Millions)
Gas and electric utilities	$	7	$	8
Energy marketers and traders		—		133
Financial institutions		432		432
	$	439		573
Credit reserves				—
Gross credit exposure from derivatives			$	573

Net credit exposure from derivative contracts

	Investment
Counterparty Type	Grade(a)		Total
	(Millions)
Gas and electric utilities	$	3	$	3
Financial institutions		317		317
	$	320		320
Credit reserves				—
Net credit exposure from derivatives			$	320

(a) We determine investment grade primarily using publicly available credit ratings. We include counterparties with a minimum Standard & Poor’s rating of BBB- or Moody’s Investors Service rating of Baa3 in investment grade.