Physical Delivery Contracts and Commodity Derivatives (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Commodity derivative assets:
Derivative Asset	$ 147
Other long-term assets	4
Commodity derivative liabilities:
Current liabilities		226
Long-term liabilites		100
Gross Recognized Assets/Liabilities [Member]
Commodity derivative assets:
Derivative Asset	215
Other long-term assets	14
Total derivative assets	229
Commodity derivative liabilities:
Current liabilities	68
Long-term liabilites	10
Total derivative liabilities	78
Gross Amounts Offset [Member]
Commodity derivative assets:
Derivative Asset	(68)
Other long-term assets	(10)
Total derivative assets	(78)
Commodity derivative liabilities:
Current liabilities	(68)
Long-term liabilites	(10)
Total derivative liabilities	(78)
Net Recognized Fair Value Assets/Liabilities [Member]
Commodity derivative assets:
Derivative Asset	147
Other long-term assets	4
Total derivative assets	151
Commodity derivative liabilities:
Current liabilities
Long-term liabilites
Total derivative liabilities