Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Commodity Derivative Positions

The following table sets forth our commodity derivative positions as of June 30, 2013:

		Average
		Volume Per	Weighted Average Price				Fair Value
	Instrument	Day	Floor/Swap		Ceiling		Asset		Liability
Crude Oil:		(barrels)	($/barrel)
Third quarter 2013	Collars	1,900	$	90.00	$	99.17	$	—	$	68
Fourth quarter 2013	Collars	1,900	$	90.00	$	99.17	110		—
First quarter 2014	Collars	500	$	90.00	97.60		74		—
Second quarter 2014	Collars	500	$	90.00	97.60		131		—
Third quarter 2013	Swaps	6,500	$	95.61			1,273		1,566
Fourth quarter 2013	Swaps	6,500	$	95.61			1,720		837
First quarter 2014	Swaps	6,000	$	93.60			1,494		682
Second quarter 2014	Swaps	6,000	$	93.60			1,778		142
Third quarter 2014	Swaps	5,500	$	92.91			1,862		—
Fourth quarter 2014	Swaps	5,500	$	92.91			2,433		—
First quarter 2014	Swaption	812	$	100.00			—		88
Second quarter 2014	Swaption	812	$	100.00			—		88
Third quarter 2014	Swaption	812	$	100.00			—		88
Fourth quarter 2014	Swaption	812	$	100.00			—		88
Natural Gas:		(in MMBtu)	($/MMBtu)
Third quarter 2013	Collars	10,000	$	3.50	$	4.30	69		—
Fourth quarter 2013	Collars	15,000	$	3.67	$	4.37	277		—
First quarter 2014	Collars	5,000	$	4.00	$	4.50	113		—
Third quarter 2013	Swaps	15,000	$	3.92			426		—
Fourth quarter 2013	Swaps	10,000	$	4.04			335		—
First quarter 2014	Swaps	10,000	$	4.28			346		—
Second quarter 2014	Swaps	15,000	$	4.10			388		—
Third quarter 2014	Swaps	15,000	$	4.10			285		—
Fourth quarter 2014	Swaps	5,000	$	4.50			211		—
First quarter 2015	Swaps	5,000	$	4.50			119		—
Settlements to be received in subsequent period							292		—

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 Condensed Consolidated Statements of Operations. The following table summarizes the effects of our derivative activities for the periods presented:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013			2012
Impact by contract type:
Commodity contracts	$	8,588	$	41,821	$	827		$	42,115
Interest rate contracts	—		2,005		—			1,406
	$	8,588	$	43,826	$	827		$	43,521
Realized and unrealized impact:
Cash received for:
Commodity contract settlements	$	2,233	$	5,564	$	5,790		$	13,545
Interest rate contract settlements	—		1,406		—			1,406
	2,233		6,970		5,790			14,951
Unrealized gains (losses) attributable to:
Commodity contracts	6,355		36,257		(4,963		)	28,570
Interest rate contracts	—		599		—			—
	6,355		36,856		(4,963		)	28,570
	$	8,588	$	43,826	$	827		$	43,521

Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets

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

		Fair Values as of
		June 30, 2013				December 31, 2012
		Derivative		Derivative		Derivative		Derivative
Type	Balance Sheet Location	Assets		Liabilities		Assets		Liabilities
Commodity contracts	Derivative assets/liabilities - current	$	9,142	$	3,963	$	11,292	$	—
Interest rate contracts	Derivative assets/liabilities - current	—		—		—		—
		9,142		3,963		11,292		—
Commodity contracts	Derivative assets/liabilities - noncurrent	4,910		—		5,181		1,421
Interest rate contracts	Derivative assets/liabilities - noncurrent	—		—		—		—
		4,910		—		5,181		1,421
		$	14,052	$	3,963	$	16,473	$	1,421