Acquisitions and Divestitures (Details) (USD $)	Sep. 30, 2011
Notes To Financial Statements [Abstract]
Additional Ownership Interest Acquired by Company in Planned Natural Gas Pipeline	24.50%
Purchase Price to Acquire Additional Interest in Planned Natural Gas Pipeline	$ 25,200,000
Portion of Purchase Price to Acquire Additional Interest in Planned Natural Gas Pipeline Paid at Closing	15,300,000
Operator Ownership Interest in Proposed LNG Terminal and Pipeline Project Subsequent to Sell-down	40.00%
Company's Interest in Proposed LNG Terminal and Pipeline Project Subsequent to Sell-down	30.00%
Interest in Proposed LNG Terminal and Pipeline Project Acquired by Third-party in Sell-down Transactions	30.00%
Estimated Proceeds from Sales of Producing Properties and Acreage an Certain Midstream Assets	$ 1.3