Assets Held for Development (Project Details) (Details) (USD $)				6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Echelon Infrastructure	Jun. 30, 2012 Minimum Echelon Infrastructure	Jun. 30, 2012 Minimum Echelon Central Energy Facility	Jun. 30, 2012 Maximum Echelon Infrastructure	Jun. 30, 2012 Maximum Echelon Central Energy Facility
Assets Held for Development [Line Items]
Expected capitalized construction costs during remainder of year			$ 4,200,000
Expected future annual capitalized construction costs				300,000		500,000
Expected future annual construction costs to be expensed during project suspension				15,500,000		17,000,000
Assets held for development	$ 1,090,198,000	$ 1,089,819,000
Property and equipment, estimated useful lives					5 years		50 years