Derivatives and Fair Value (Notional) (Detail)	1 Months Ended	6 Months Ended
Apr. 30, 2016 $ / Boe	Jun. 30, 2016 bbl
Derivative, Nonmonetary Notional Amount per Month \| bbl		36,000
Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Underlying, Derivative Energy Measure \| $ / Boe	40.00

Specified interest rate, security price, commodity price, foreign exchange rate, index of prices or rates for a derivative contract measured in energy volume but not the derivative contract itself.

No definition available.

Name:	us-gaap_UnderlyingDerivativeEnergyMeasure
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration