Fair Value Measurements and Disclosures (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Measurement information for assets and liabilities that are measured at fair value on a recurring basis was as follows: 

	Fair Value Measurements Using
	Quoted Prices in  Active Markets (Level 1) (1)			Significant Other Observable Inputs (Level 2) (2)			Significant Unobservable Inputs (Level 3) (3)		Adjustment (4)			Fair Value Measurement
(millions)
March 31, 2013
Financial Assets
Mutual Fund Investments	$	109		$	—		$	—	$	—		$	109
Commodity Derivative Instruments	—			62			—		(13		)	49
Financial Liabilities
Commodity Derivative Instruments	—			(66		)	—		13			(53		)
Portion of Deferred Compensation Liability Measured at Fair Value	(174		)	—			—		—			(174		)
December 31, 2012
Financial Assets
Mutual Fund Investments	$	103		$	—		$	—	$	—		$	103
Commodity Derivative Instruments	—			113			—		(29		)	84
Financial Liabilities
Commodity Derivative Instruments	—			(39		)	—		29			(10		)
Portion of Deferred Compensation Liability Measured at Fair Value	(160		)	—			—		—			(160		)

⁽¹⁾  Level 1 measurements are fair value measurements which use quoted market prices (unadjusted) in active markets for identical assets or liabilities. We use Level 1 inputs when available as Level 1 inputs generally provide the most reliable evidence of fair value.

⁽²⁾  Level 2 measurements are fair value measurements which use inputs, other than quoted prices included within Level 1, which are observable for the asset or liability, either directly or indirectly.

⁽³⁾  Level 3 measurements are fair value measurements which use unobservable inputs.

⁽⁴⁾  Amount represents the impact of netting clauses within our master agreements that allow us to net cash settle asset and liability positions with the same counterparty.

Additional fair value disclosures

Fair value information regarding our debt is as follows: 

	March 31, 2013				December 31, 2012
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
(millions)
Total Debt, Net of Unamortized Discount (1)	$	3,798	$	4,539	$	3,797	$	4,570

⁽¹⁾  Excludes Aseng FPSO lease obligation. No floating rate debt was outstanding at March 31, 2013 or December 31, 2012.