Financial Instruments Fair Value Disclosures (Details Textual) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Financial Instruments [Abstract]
Level 2 and level 3 fair value transactions	$ 0
Derivative Asset, Fair Value, Net	1,100,000	800,000
Margin Deposit Assets	$ 900,000	$ 1,900,000