Annual report pursuant to Section 13 and 15(d)

Commitments And Contingencies (Details)

v2.4.0.6
Commitments And Contingencies (Details) (USD $)
12 Months Ended
Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]  
Expansion and enhancement contracts $ 7,500,000
Sovran HHF Storage Holdings II LLC [Member]
 
Schedule of Equity Method Investments [Line Items]  
Consideration paid for facilities 29,000,000
Number of facilities acquired 10
Percentage ownership in joint venture 15
Cash contributed to the joint venture $ 4,300,000