Asset Acquisition (Details Textuals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Business Acquisition [Line Items]
Business Acquisition, Name of Acquired Entity	LIG Pipeline
Clearfield Energy [Member]
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement	Jul. 02, 2012
Business Acquisition, Name of Acquired Entity	Clearfield Energy, Inc
Business Acquisition, Cost of Acquired Entity, Purchase Price	214,957
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years
Right Of Way Option Life	10 years
Business Acquisition, Purchase Price Allocation, Current Assets, Asset Held-for-sale	19,500
Business Sale Agreement Date	Oct. 15, 2012
Assets Held for Sale Date of Sale	Jan. 18, 2013