Commitments and Contingencies (Details) (USD $)	1 Months Ended	6 Months Ended		6 Months Ended		12 Months Ended
	Feb. 28, 2009 Parties	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Cooperating Parties Group [Member] Parties	Jun. 30, 2012 MTBE [Member] Parties	Dec. 31, 2010 MTBE [Member] Case
Commitments and Contingencies (Textual) [Abstract]
Parties to Perform a Remedial Investigation and Feasibility Study				70
Petroleum Refiners, Manufacturers, Distributors and Retailers					50
Agreements to Settle						$ 1,725,000
Classes Covering						2
Pending Cases						52
Commitments and Contingencies (Additional Textual) [Abstract]
Administrative Claims		10,500,000
Accrued legal matters		$ 3,771,000	$ 4,242,000
Number of additional parties	300
Percentage of taxable income distributed among stockholders		90.00%
Percentage of common stock to total required distribution		90.00%