Commitments and Contingencies - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule of Commitments and Contingencies (Details) [Line Items]
Financing and capital lease obligations non current	$ 9,956,000		$ 10,092,000
Operating Leases, Rent Expense	$ 436,000	$ 66,000
Solar Modules [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Warranty Term	25 years
Inverter and balance of system components [Member] | Minimum [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Warranty Term	5 years
Inverter and balance of system components [Member] | Maximum [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Warranty Term	10 years
Solar Energy Systems [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Product Warranty Accrual	$ 0		0
Photovoltaic (PV) Solar Systems [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Long-term Purchase Commitment, Amount	56,468,000		59,354,000
Aerojet1 Project [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Guarantees, Fair Value Disclosure	67,000		71,000
Aerojet1 Project [Member] | Guarantee Obligations [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Financing and capital lease obligations total	10,775,000		10,911,000
Financing and capital lease obligations non current	9,956,000		10,092,000
Financing and capital lease obligations recorded as other current liabilities	819,000		$ 819,000
Greystone [Member]
Schedule of Commitments and Contingencies (Details) [Line Items]
Redeemable Noncontrolling Interest, Equity, Carrying Amount	$ 1,000,000