Commitments and Contingencies (Details 2) (USD $)	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Commitments And Contingencies (Textuals) [Abstract]
Percentage cover by capacity release agreements	100.00%		100.00%
Escrow cash	$ 1,850,000		$ 1,850,000		$ 1,856,000
Total rental expense	$ 1,133,000	$ 855,000	$ 2,057,000	$ 1,733,000
Quantity of natural gas (cubic feet)	2,373,000,000		2,373,000,000

Rental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 15

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph c

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration