Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

Fair Value Measurements

Derivative instrument assets and liabilities measured at fair value on a recurring basis

			Fair value measurements at reporting date using
Description	December 31, 2013		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
	(Thousands)
Assets
Derivative instruments, at fair value	$	107,647	$	240	$	107,407	$	–
Liabilities
Derivative instruments, at fair value	$	29,651	$	315	$	29,336	$	–

			Fair value measurements at reporting date using
Description	December 31, 2012		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
	(Thousands)
Assets
Derivative instruments, at fair value	$	304,237	$	1,228	$	204,592	$	98,417
Liabilities
Derivative instruments, at fair value	$	75,562	$	1,609	$	66,250	$	7,703

Fair value measurements using significant unobservable inputs (Level 3)

Fair value measurements using significant unobservable inputs (Level 3) Derivative instruments, at fair value, net
	Years Ended December 31,
	2013		2012
	(Thousands)
Balance at January 1	$	90,714	$	143,260
Total gains or losses:
Included in earnings	640		(615)
Included in OCI	(2,554)		23,386
Purchases	–		(933)
Settlements	(34,381)		(74,384)
Transfers in and/or out of Level 3	(54,419)		–
Balance at December 31	$	–	$	90,714