Fair Value Measurements

12 Months Ended

Dec. 31, 2011

Fair Value Measurements [Abstract]

Fair Value Measurements

11. Fair Value Measurements

The Company reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities at December 31 that were accounted for at fair value on a recurring basis:

	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

	2010
	Level 1			Level 2		Total
Derivative instruments
Risk management assets	$	47		$	—	$	47
Risk management liabilities		(46	)		—		(46	)

The Level 2 measurements are derived using forward curves supplied by industry recognized and unrelated third-party services. There were no transfers in and out of Levels 1 and 2 of the fair value hierarchy in 2011 and 2010.

See Note 16 for the measurement of certain assets at fair value on a nonrecurring basis.

In addition to the assets and liabilities above, the Company has other financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt, all of which are recorded at carrying value. The carrying amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Company's long-term debt at December 31 are summarized below:

	2011				2010
	Carrying Value		Fair Value		Carrying Value		Fair Value
6 5/8% senior notes due 2016	$	249,674	$	254,890	$	249,593	$	258,438
6 1/2% senior notes due 2029		100,000		108,834		100,000		99,875
6 3/4% senior notes due 2032		250,000		263,988		250,000		251,925
2035 GO Zone 6 1/2% Notes		89,000		93,090		89,000		88,653
2035 IKE Zone 6 1/2% Notes		65,000		67,987		65,000		64,905
Variable rate tax-exempt waste disposal revenue bonds due 2027		10,889		10,889		10,889		10,889