Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Other Securities (Details Textual)

v2.4.0.6
Fair Value of Other Securities (Details Textual) (USD $)
Share data in Millions, unless otherwise specified
 1 Months Ended 3 Months Ended 1 Months Ended 3 Months Ended
Dec. 31, 2012
Mar. 31, 2013
Feb. 29, 2012
Nov. 30, 2011
High Sierra Energy [Member]
Aug. 31, 2012
High Sierra Energy [Member]
Dec. 31, 2012
Lightfoot Capital Partners LP [Member]
Dec. 31, 2012
Vantacore Partners LP [Member]
Schedule of Equity Method Investments [Line Items]              
Equity Method Investment, Ownership Percentage           6.70% 11.10%
Fair Value of Financial Instruments (Textual) [Abstract]              
Consideration paid in cash for acquisition       $ 9,400,000      
Consideration paid in newly issued units       1.2      
Gains and losses on sales of securities (6,432,269) (434,941) 2,862,272   15,800,000    
Transfers out 4,320,000            
Fair Value of Financial Instruments (Additional Textual) [Abstract]              
Transfers between levels 0 0 0        
Minimum period for releasing of escrow receivable   14 months          
Remaining amount of escrow receivable   $ 699,000