Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2012

Summary Of Assets And Liabilities Accounted At Fair Value On A Recurring Basis

The following tables summarize, by level within the fair value hierarchy, the Company’s assets and liabilities that were accounted for at fair value on a recurring basis:

	June 30, 2012
	Level 1			Level 2			Total
Derivative instruments
Risk management assets—Commodity forward contracts	$	1,379		$	8,670		$	10,049
Risk management liabilities—Commodity forward contracts		—			(2,884	)		(2,884	)
Risk management liabilities—Treasury lock agreements		(813	)		—			(813	)
Firm commitments
Hedged portion of firm commitment		—			544			544
Hedged portion of firm commitment		—			(8,670	)		(8,670	)
Marketable securities
Available-for-sale equity securities		1,288			—			1,288
	December 31, 2011
	Level 1			Level 2			Total
Derivative instruments
Risk management assets	$	1,090		$	1,347		$	2,437
Risk management liabilities		—			(4,235	)		(4,235	)
Firm commitments
Hedged portion of firm commitment		—			3,262			3,262
Marketable securities
Available-for-sale equity securities		30,113			—			30,113

Summary Of Carrying And Fair Values Of Long-Term Debt

	June 30, 2012				December 31, 2011
	Carrying Value		Fair Value		Carrying Value		Fair Value
65/8% senior notes due 2016	$	249,715	$	252,160	$	249,674	$	254,890
6   1/2% senior notes due 2029		100,000		115,575		100,000		108,834
6   3/4% senior notes due 2032		250,000		280,583		250,000		263,988
2035 GO Zone 6  1/2% Notes		89,000		89,619		89,000		93,090
2035 IKE Zone 6  1/2% Notes		65,000		65,452		65,000		67,987
Loan related to tax-exempt waste disposal revenue bonds due 2027		10,889		10,889		10,889		10,889