Commodity Derivative Positions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2014 bbl
Settlements to be received (paid) in subsequent period
Derivative Instruments Related to Oil and Gas Production [Line Items]
Fair Value Asset	$ 52
Fair Value Liability	0
Crude Oil | Group One
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Collars
Derivative, Nonmonetary Notional Amount	2,000
Weighted Average Price, Floor/Swap	90.00
Weighted Average Price, Ceiling	94,330.00
Fair Value Asset	264
Fair Value Liability	0
Crude Oil | Group Two
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Collars
Derivative, Nonmonetary Notional Amount	4,000
Weighted Average Price, Floor/Swap	87.50
Weighted Average Price, Ceiling	94,660.00
Fair Value Asset	649
Fair Value Liability	0
Crude Oil | Group Three
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Collars
Derivative, Nonmonetary Notional Amount	4,000
Weighted Average Price, Floor/Swap	87.50
Weighted Average Price, Ceiling	94,660.00
Fair Value Asset	947
Fair Value Liability	0
Crude Oil | Group Four
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Collars
Derivative, Nonmonetary Notional Amount	3,000
Weighted Average Price, Floor/Swap	86.67
Weighted Average Price, Ceiling	94,730.00
Fair Value Asset	770
Fair Value Liability	0
Crude Oil | Group Five
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Collars
Derivative, Nonmonetary Notional Amount	3,000
Weighted Average Price, Floor/Swap	86.67
Weighted Average Price, Ceiling	94,730.00
Fair Value Asset	838
Fair Value Liability	0
Crude Oil | Group Six
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	11,000
Derivative, Swap Type, Average Fixed Price	93.45
Fair Value Asset	3,301
Fair Value Liability	40
Crude Oil | Group Seven
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	9,000
Derivative, Swap Type, Average Fixed Price	91.81
Fair Value Asset	2,197
Fair Value Liability	0
Crude Oil | Group Eight
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	9,000
Derivative, Swap Type, Average Fixed Price	91.81
Fair Value Asset	2,835
Fair Value Liability	0
Crude Oil | Group Nine
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	8,000
Derivative, Swap Type, Average Fixed Price	91.06
Fair Value Asset	2,352
Fair Value Liability	0
Crude Oil | Group Ten
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	8,000
Derivative, Swap Type, Average Fixed Price	91.06
Fair Value Asset	2,432
Fair Value Liability	0
Crude Oil | Group Eleven
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	90.84
Fair Value Asset	1,176
Fair Value Liability	0
Crude Oil | Group Twelve
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	90.84
Fair Value Asset	1,284
Fair Value Liability	0
Crude Oil | Group Thirteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	90.84
Fair Value Asset	1,395
Fair Value Liability	0
Crude Oil | Group Fourteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Derivative, Nonmonetary Notional Amount	3,000
Derivative, Swap Type, Average Fixed Price	90.84
Fair Value Asset	1,447
Fair Value Liability	0
Crude Oil | Group Fifteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88.00
Fair Value Asset	0
Fair Value Liability	252
Crude Oil | Group Sixteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88.00
Fair Value Asset	0
Fair Value Liability	251
Crude Oil | Group Seventeen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88.00
Fair Value Asset	0
Fair Value Liability	251
Crude Oil | Group Eighteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88.00
Fair Value Asset	0
Fair Value Liability	251
Natural Gas | Group Nineteen
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Average Volume Per Day (MMBtu)	5,000
Weighted Average Price, Floor/Swap	4.50
Fair Value Asset	185
Fair Value Liability	0
Natural Gas | Group Twenty
Derivative Instruments Related to Oil and Gas Production [Line Items]
Instrument	Swaps
Average Volume Per Day (MMBtu)	5,000
Weighted Average Price, Floor/Swap	4.50
Fair Value Asset	129
Fair Value Liability	$ 0