Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability)	$ (346)
Open costless collar contracts [Member] | Oil [Member]
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability)	1,534
Open costless collar contracts [Member] | Oil [Member] | Oil contract 1 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	20,000
Price Floor	85.00
Price Ceiling	102.25
Fair Value of Asset (Liability)	(140)
Open costless collar contracts [Member] | Oil [Member] | Oil contract 2 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	20,000
Price Floor	90.00
Price Ceiling	115.00
Fair Value of Asset (Liability)	292
Open costless collar contracts [Member] | Oil [Member] | Oil contract 3 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	20,000
Price Floor	85.00
Price Ceiling	110.40
Fair Value of Asset (Liability)	96
Open costless collar contracts [Member] | Oil [Member] | Oil contract 4 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	20,000
Price Floor	85.00
Price Ceiling	108.80
Fair Value of Asset (Liability)	71
Open costless collar contracts [Member] | Oil [Member] | Oil contract 5 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 06/30/2014
Notional Quantity	8,000
Price Floor	90.00
Price Ceiling	114.00
Fair Value of Asset (Liability)	324
Open costless collar contracts [Member] | Oil [Member] | Oil contract 6 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 06/30/2014
Notional Quantity	12,000
Price Floor	90.00
Price Ceiling	115.50
Fair Value of Asset (Liability)	502
Open costless collar contracts [Member] | Oil [Member] | Oil contract 7 [Member]
Summary of contracts for oil and natural gas
Calculation Period	07/01/2013 - 12/31/2013
Notional Quantity	20,000
Price Floor	90.00
Price Ceiling	102.80
Fair Value of Asset (Liability)	49
Open costless collar contracts [Member] | Oil [Member] | Oil contract 8 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	15,000
Price Floor	85.00
Price Ceiling	97.50
Fair Value of Asset (Liability)	(122)
Open costless collar contracts [Member] | Oil [Member] | Oil contract 9 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	30,000
Price Floor	85.00
Price Ceiling	98.00
Fair Value of Asset (Liability)	(179)
Open costless collar contracts [Member] | Oil [Member] | Oil contract 10 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	15,000
Price Floor	87.00
Price Ceiling	97.00
Fair Value of Asset (Liability)	(41)
Open costless collar contracts [Member] | Oil [Member] | Oil contract 11 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	20,000
Price Floor	90.00
Price Ceiling	97.00
Fair Value of Asset (Liability)	209
Open costless collar contracts [Member] | Oil [Member] | Oil contract 12 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	15,000
Price Floor	90.00
Price Ceiling	97.90
Fair Value of Asset (Liability)	238
Open costless collar contracts [Member] | Oil [Member] | Oil contract 13 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	15,000
Price Floor	90.00
Price Ceiling	98.00
Fair Value of Asset (Liability)	235
Open costless collar contracts [Member] | Natural Gas [Member]
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability)	(1,378)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 1 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 07/31/2013
Notional Quantity	150,000
Price Floor	4.50
Price Ceiling	5.75
Fair Value of Asset (Liability)	297
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 2 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.00
Price Ceiling	3.83
Fair Value of Asset (Liability)	(359)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 3 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.00
Price Ceiling	4.95
Fair Value of Asset (Liability)	(46)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 4 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.00
Price Ceiling	4.96
Fair Value of Asset (Liability)	(45)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 5 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	4.41
Fair Value of Asset (Liability)	(114)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 6 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	4.44
Fair Value of Asset (Liability)	(107)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 7 [Member]
Summary of contracts for oil and natural gas
Calculation Period	04/01/2013 - 12/31/2013
Notional Quantity	100,000
Price Floor	3.50
Price Ceiling	4.37
Fair Value of Asset (Liability)	(100)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 8 [Member]
Summary of contracts for oil and natural gas
Calculation Period	07/01/2013 - 12/31/2013
Notional Quantity	150,000
Price Floor	3.00
Price Ceiling	4.24
Fair Value of Asset (Liability)	(238)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 9 [Member]
Summary of contracts for oil and natural gas
Calculation Period	08/01/2013 - 12/31/2013
Notional Quantity	80,000
Price Floor	3.75
Price Ceiling	4.57
Fair Value of Asset (Liability)	(15)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 10 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.00
Price Ceiling	5.15
Fair Value of Asset (Liability)	(153)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 11 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	5.21
Fair Value of Asset (Liability)	(89)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 12 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	5.22
Fair Value of Asset (Liability)	(88)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 13 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	5.37
Fair Value of Asset (Liability)	(68)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 14 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.25
Price Ceiling	5.42
Fair Value of Asset (Liability)	(60)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 15 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.50
Price Ceiling	4.90
Fair Value of Asset (Liability)	(94)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 16 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2014 - 12/31/2014
Notional Quantity	100,000
Price Floor	3.75
Price Ceiling	4.77
Fair Value of Asset (Liability)	(48)
Open costless collar contracts [Member] | Natural Gas [Member] | Natural Gas contract 17 [Member]
Summary of contracts for oil and natural gas
Calculation Period	01/01/2015 - 12/31/2015
Notional Quantity	200,000
Price Floor	3.75
Price Ceiling	5.04
Fair Value of Asset (Liability)	(51)
Open Swap Contracts [Member] | Oil [Member]
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability)	(1,142)
Open Swap Contracts [Member] | Oil [Member] | Open Swap Contracts for Oil One [Member]
Summary of contracts for oil and natural gas
Calculation Period	04-01-2013 - 12-31-2013
Notional Quantity	10,000
Price Floor	90.20
Fair Value of Asset (Liability)	(591)
Open Swap Contracts [Member] | Oil [Member] | Open Swap Contracts for Oil Two [Member]
Summary of contracts for oil and natural gas
Calculation Period	04-01-2013 - 12-31-2013
Notional Quantity	10,000
Price Floor	90.65
Fair Value of Asset (Liability)	$ (551)