Quarterly report pursuant to Section 13 or 15(d)

Reconciliation of Gross Assets and Liabilities and Netting Agreements on Fair Value of Open Derivative Contracts (Detail)

v2.4.0.8
Reconciliation of Gross Assets and Liabilities and Netting Agreements on Fair Value of Open Derivative Contracts (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Derivative Assets    
Fair value of commodity derivative contracts   $ 141
Amounts not offset in the balance sheet   (141)
Derivative Liabilities    
Fair value of commodity derivative contracts 12,104 9,423
Amounts not offset in the balance sheet   (141)
Net Amounts $ 12,104 $ 9,282