Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2012

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Commodity Derivative Positions

The following table sets forth our commodity derivative positions as of December 31, 2012:

		Average
		Volume Per	Weighted Average Price				Fair Value
	Instrument	Day	Floor/Swap		Ceiling		Asset		Liability
Crude Oil:		(barrels)	($/barrel)
First quarter 2013	Collars	1,000	$	90.00	$	100.00	$	119	$	—
Second quarter 2013	Collars	1,000	$	90.00	$	100.00	124		—
Third quarter 2013	Collars	1,000	$	90.00	$	100.00	123		—
Fourth quarter 2013	Collars	1,000	$	90.00	$	100.00	151		—
First quarter 2013	Swaps	2,250	$	103.51			2,244		—
Second quarter 2013	Swaps	2,250	$	103.51			2,040		—
Third quarter 2013	Swaps	1,500	$	102.77			1,248		—
Fourth quarter 2013	Swaps	1,500	$	102.77			1,296		—
First quarter 2014	Swaps	2,000	$	100.44			1,360		—
Second quarter 2014	Swaps	2,000	$	100.44			1,446		—
Third quarter 2014	Swaps	1,500	$	100.20			1,128		—
Fourth quarter 2014	Swaps	1,500	$	100.20			1,179		—
First quarter 2014	Swaption	812	$	100.00			—		356
Second quarter 2014	Swaption	812	$	100.00			—		355
Third quarter 2014	Swaption	812	$	100.00			—		355
Fourth quarter 2014	Swaption	812	$	100.00			—		355
Natural Gas:		(in MMBtu)	($/MMBtu)
First quarter 2013	Collars	10,000	$	3.50	$	4.30	187		—
Second quarter 2013	Collars	10,000	$	3.50	$	4.30	219		—
Third quarter 2013	Collars	10,000	$	3.50	$	4.30	165		—
Fourth quarter 2013	Collars	15,000	$	3.67	$	4.37	216		—
First quarter 2014	Collars	5,000	$	4.00	$	4.50	68		—
First quarter 2013	Swaps	10,000	$	4.01			587		—
Second quarter 2013	Swaps	10,000	$	4.01			504		—
Third quarter 2013	Swaps	10,000	$	4.01			391		—
Fourth quarter 2013	Swaps	5,000	$	4.04			121		—
Settlements to be received in subsequent period							1,557		—

Impact of Derivative Activities on Condensed Consolidated Statements of Income

The impact of our derivatives activities on income is included in the Derivatives caption on our Consolidated Statements of Operations. The following table summarizes the effects of our derivative activities for the periods presented:

	Year Ended December 31,
	2012		2011			2010
Impact by contract type:
Commodity contracts	$	34,781	$	14,422		$	36,693
Interest rate contracts	1,406		1,229			5,213
	$	36,187	$	15,651		$	41,906
Realized and unrealized impact:
Cash received (paid) for:
Commodity contract settlements	$	28,317	$	23,562		$	33,480
Interest rate contract settlements	1,406		3,818			(662		)
	29,723		27,380			32,818
Unrealized gains (losses) attributable to:
Commodity contracts	6,464		(9,140		)	3,213
Interest rate contracts	—		(2,589		)	5,875
	6,464		(11,729		)	9,088
	$	36,187	$	15,651		$	41,906

Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets

The following table summarizes the fair value of our derivative instruments, as well as the locations of these instruments, on our Consolidated Balance Sheets as of the dates presented:

		Fair Values as of
		December 31, 2012				December 31, 2011
		Derivative		Derivative		Derivative		Derivative
Type	Balance Sheet Location	Assets		Liabilities		Assets		Liabilities
Commodity contracts	Derivative assets/liabilities - current	$	11,292	$	—	$	18,987	$	3,549
Interest rate contracts	Derivative assets/liabilities - current	—		—		—		—
		11,292		—		18,987		3,549
Commodity contracts	Derivative assets/liabilities - noncurrent	5,181		1,421		—		6,850
Interest rate contracts	Derivative assets/liabilities - noncurrent	—		—		—		—
		5,181		1,421		—		6,850
		$	16,473	$	1,421	$	18,987	$	10,399