Investment in Unconsolidated Affiliates - Summary of Financial Information (Details) - Solar Gen Two Holdings North Star Holdings Lost Hills Blackwell Holdings Henrietta Holdings And Stateline Holdings - USD ($) $ in Thousands	3 Months Ended
	Feb. 28, 2018	Feb. 28, 2017
Summary statements of operations information:
Revenue	$ 24,177	$ 19,616
Operating expenses	26,290	26,393
Net loss	$ (2,357)	$ (7,759)