Solar Energy Systems, Leased and To Be Leased - Net - Components of Solar Energy Systems, Leased and to Be Leased (Detail) - Solar Energy Systems [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property Subject To Or Available For Operating Lease [Line Items]
Solar energy systems leased to customers	$ 5,878,322	$ 5,052,976
Initial direct costs related to customer solar energy system lease acquisition costs	65,283	12,774
Solar energy systems, leased and to be leased, gross	5,943,605	5,065,750
Less: accumulated depreciation and amortization	(168,571)	(20,157)
Solar energy systems, leased and to be leased gross, less accumulated depreciation and amortization	5,775,034	5,045,593
Solar energy systems under construction	241,928	460,913
Solar energy systems to be leased to customers	271,003	413,374
Solar energy systems, leased and to be leased – net	$ 6,287,965	$ 5,919,880