Commodity Derivative Positions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 bbl
Settlements to be paid in subsequent period
Derivative Instruments Related to Oil and Gas Production [Line Items]
Fair Value Asset	$ 0
Fair Value Liability	423
Crude Oil | Group Three
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	91.92
Fair Value Asset	88
Fair Value Liability	0
Crude Oil | Group Four
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	91.92
Fair Value Asset	435
Fair Value Liability	0
Crude Oil | Group Five
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	2,000
Derivative, Swap Type, Average Fixed Price	91.48
Fair Value Asset	410
Fair Value Liability	0
Crude Oil | Group Six
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2013
Instrument	Collars
Derivative, Nonmonetary Notional Amount	1,500
Weighted Average Price, Floor/Swap	93.33
Weighted Average Price, Ceiling	102.80
Fair Value Asset	0
Fair Value Liability	28
Crude Oil | Group Seven
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2013
Instrument	Collars
Derivative, Nonmonetary Notional Amount	1,500
Weighted Average Price, Floor/Swap	93.33
Weighted Average Price, Ceiling	102.80
Fair Value Asset	128
Fair Value Liability	0
Crude Oil | Group Eight
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	2,000
Derivative, Swap Type, Average Fixed Price	91.48
Fair Value Asset	556
Fair Value Liability	0
Crude Oil | Group Nine
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2013
Crude Oil | Group Ten
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2013
Crude Oil | Group Eleven
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2014
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	8,500
Derivative, Swap Type, Average Fixed Price	94.00
Fair Value Asset	0
Fair Value Liability	3,352
Crude Oil | Group Twelve
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2014
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	8,500
Derivative, Swap Type, Average Fixed Price	94.00
Fair Value Asset	0
Fair Value Liability	2,280
Crude Oil | Group Thirteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2014
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	9,000
Derivative, Swap Type, Average Fixed Price	93.38
Fair Value Asset	0
Fair Value Liability	1,025
Crude Oil | Group Fourteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2014
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	9,000
Derivative, Swap Type, Average Fixed Price	93.38
Fair Value Asset	607
Fair Value Liability	0
Crude Oil | Group Fifteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2014
Crude Oil | Group Sixteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2014
Crude Oil | Group Seventeen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2014
Crude Oil | Group Eighteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2014
Natural Gas | Group Nine
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	5,000
Derivative, Swap Type, Average Fixed Price	4.50
Fair Value Asset	64
Fair Value Liability	0
Natural Gas | Group Nineteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2013
Instrument	Collars
Derivative, Nonmonetary Notional Amount	5,000
Weighted Average Price, Floor/Swap	4.00
Weighted Average Price, Ceiling	4.50
Fair Value Asset	0
Fair Value Liability	3
Natural Gas | Group Twenty
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2013
Natural Gas | Group Twenty One
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2013
Natural Gas | Group Twenty Two
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2013
Natural Gas | Group Twenty Three [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2014
Natural Gas | Group Twenty Four
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Mar. 31, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	10,000
Derivative, Swap Type, Average Fixed Price	4.28
Fair Value Asset	1
Fair Value Liability	0
Natural Gas | Group Twenty Five
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Jun. 30, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	15,000
Derivative, Swap Type, Average Fixed Price	4.10
Fair Value Asset	0
Fair Value Liability	1
Natural Gas | Group Twenty Six
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Sep. 30, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	15,000
Derivative, Swap Type, Average Fixed Price	4.10
Fair Value Asset	0
Fair Value Liability	60
Natural Gas | Group Twenty Seven
Derivative Instruments Related to Oil and Gas Production [Line Items]
Term	Dec. 31, 2013
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	5,000
Derivative, Swap Type, Average Fixed Price	4.50
Fair Value Asset	125
Fair Value Liability	$ 0