Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jan. 31, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Other Commitments [Line Items]
Letters of credit outstanding, amount	$ 5.8		$ 5.8		$ 5.8		$ 5.8
Capital Lease Obligations	11.1		11.1		$ 11.1		7.4
Solar Energy System Modules
Other Commitments [Line Items]
Purchase commitment with suppliers	32.0
Photovoltaic Modules
Other Commitments [Line Items]
Purchase commitment with suppliers		$ 70.0
Capital Lease Obligations
Other Commitments [Line Items]
Lease obligation interest rates					10.00%
Non-Cancellable Operating Leases
Other Commitments [Line Items]
Operating lease expenses			1.5	$ 0.8	$ 2.6	$ 1.5
Deferred rent liabilities	1.7		$ 1.7		$ 1.7		$ 2.0
Minimum | Inverters
Other Commitments [Line Items]
Purchase commitment with suppliers	14.0
Maximum | Inverters
Other Commitments [Line Items]
Purchase commitment with suppliers	$ 20.0
Letter of Credit | Minimum
Other Commitments [Line Items]
Letter of credit, fee percentage					2.00%
Letter of Credit | Maximum
Other Commitments [Line Items]
Letter of credit, fee percentage					2.75%