Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

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, 2015
	Level 1			Level 2			Total
Derivative instruments
Risk management assets—Commodity forward contracts	$	3,958		$	914		$	4,872
Risk management liabilities—Commodity forward contracts	(1,825		)	(4,668		)	(6,493		)
Marketable securities
Available-for-sale securities	5,074			—			5,074

	December 31, 2014
	Level 1			Level 2			Total
Derivative instruments
Risk management assets—Commodity forward contracts	$	3,143		$	2		$	3,145
Risk management liabilities—Commodity forward contracts	—			(10,108		)	(10,108		)
Marketable securities
Available-for-sale securities	15,414			—			15,414

Summary Of Carrying And Fair Values Of Long-Term Debt

The carrying and fair values of the Company's long-term debt are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy.



	June 30, 2015				December 31, 2014
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.60% senior notes due 2022	$	249,167	$	251,118	$	249,108	$	248,630
6 ½% senior notes due 2029	100,000		119,018		100,000		116,384
6 ¾% senior notes due 2032	250,000		277,375		250,000		285,545
6 ½% GO Zone Senior Notes Due 2035	89,000		104,498		89,000		106,504
6 ½% IKE Zone Senior Notes Due 2035	65,000		75,485		65,000		77,784
Loan related to tax-exempt waste disposal revenue bonds due 2027	10,889		10,889		10,889		10,889