Income Taxes (Details) (USD $)	3 Months Ended		12 Months Ended	1 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Apr. 30, 2013 Subsequent event	Mar. 31, 2013 State Colorado
Income Taxes
Decrease in valuation allowance		$ 229,700,000
Amount of valuation allowance released		54,200,000
Operating loss carryforwards
NOLs suspended in excess of amount					250,000
Reduction in deferred tax assets related to net operating losses		229,700,000	229,700,000
Income tax expense paid for alternative minimum tax	270,000			475,000
Income tax expense recorded for alternative minimum tax	$ 453,000		$ 268,000