Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2011

Fair Value Measurements

Assets and liabilities measured at fair value on a recurring basis

	Fair Value Measurements at September 30, 2011 Using
Description	Level 1		Level 2		Level 3		Netting and Collateral		(a)	Total Fair Value
Assets:
Trading equity securities — natural resources industry	$	139	$	—	$	—	$	—		$	139
Commodity derivatives	727		911		—		(1,390		)	248
Total assets	$	866	$	911	$	—	$	(1,390	)	$	387
Liabilities:
Commodity derivatives	$	697	$	1,027	$	—	$	(1,431	)	$	293
Total liabilities	$	697	$	1,027	$	—	$	(1,431	)	$	293

	Fair Value Measurements at December 31, 2010 Using
Description	Level 1		Level 2		Level 3		Netting and Collateral		(a)	Total Fair Value
Assets:
Trading equity securities — natural resources industry	$	116	$	—	$	—	$	—		$	116
Trading U.S. treasury securities	10		—		—		—			10
Commodity derivatives	178		797		—		(680		)	295
Total assets	$	304	$	797	$	—	$	(680	)	$	421
Liabilities:
Commodity derivatives	$	201	$	916	$	—	$	(736	)	$	381
Total liabilities	$	201	$	916	$	—	$	(736	)	$	381

(a)Represents the impact of netting assets, liabilities and collateral when a legal right of offset exists.