Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value Summary of Long-Term Debt with Fixed Interest Rates

The following table summarizes the fair value of our long-term debt with fixed interest rates, which is estimated based on the published market prices for these debt obligations as of the dates presented:

	March 31, 2012				December 31, 2011
	Fair		Carrying		Fair		Carrying
	Value		Value		Value		Value
Senior Notes due 2016	$	300,000	$	293,848	$	319,500	$	293,561
Senior Notes due 2019		256,950		300,000		280,500		300,000
Convertible Notes		4,915		4,791		4,925		4,746
	$	561,865	$	598,639	$	604,925	$	598,307

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables summarize the fair values of those assets and liabilities as of the dates presented:

	As of March 31, 2012
	Fair Value			Fair Value Measurement Classification
Description	Measurement			Level 1			Level 2			Level 3
Assets:
Commodity derivative assets - current	$	14,492		$	-		$	14,492		$	-
Commodity derivative assets - noncurrent		1,167			-			1,167			-
Interest rate swap assets - current		344						344
Assets of SERP		3,339			3,339			-			-
Liabilities:
Commodity derivative liabilities - current		(7,262	)		-			(7,262	)		-
Commodity derivative liabilities - noncurrent		(7,494	)		-			(7,494	)		-
Interest rate swap liabilities - noncurrent		(943	)					(943	)
Deferred compensation - SERP obligation and other		(3,409	)		(3,409	)		-			-
	$	234		$	(70	)	$	304		$	-

	As of December 31, 2011
	Fair Value			Fair Value Measurement Classification
Description	Measurement			Level 1			Level 2			Level 3
Assets:
Commodity derivative assets – current	$	18,987		$	-		$	18,987		$	-
Assets of SERP		3,088			3,088			-			-
Liabilities:
Commodity derivative liabilities - current		(3,549	)		-			(3,549	)		-
Commodity derivative liabilities - noncurrent		(6,850	)		-			(6,850	)		-
Deferred compensation - SERP obligation and other		(3,168	)		(3,168	)		-			-
	$	8,508		$	(80	)	$	8,588		$	-