Fair Value (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Schedule Of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following tables summarize the carrying amounts, fair values and recurring fair value measurements recorded or disclosed as of December 31, 2015 and March 31, 2016, based on the three levels established by ASC 820, Fair Value Measurements and Disclosures (in thousands):

	As of December 31, 2015
Assets (Liabilities)							Fair Value Measurements using:
	Carrying Amount			Fair Value			Quoted Prices  in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Energy commodity derivatives contracts	$	42,721		$	42,721		$	42,721	$	—		$	—
Interest rate contracts	$	1,526		$	1,526		$	—	$	1,526		$	—
Long-term receivables	$	20,374		$	20,021		$	—	$	—		$	20,021
Debt	$	(3,439,622	)	$	(3,284,791	)	$	—	$	(3,284,791	)	$	—

	As of March 31, 2016
Assets (Liabilities)							Fair Value Measurements using:
	Carrying Amount			Fair Value			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Energy commodity derivatives contracts	$	22,592		$	22,592		$	22,592	$	—		$	—
Interest rate contracts	$	(10,951	)	$	(10,951	)	$	—	$	(10,951	)	$	—
Long-term receivables	$	20,726		$	21,272		$	—	$	—		$	21,272
Debt	$	(3,802,261	)	$	(3,884,960	)	$	—	$	(3,884,960	)	$	—