Related Party Transactions - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Enphase
Related Party Transaction [Line Items]
Purchase from related party	$ 1.4	$ 2.4	$ 14.4	$ 4.8
Outstanding payables to related party	3.1		3.1		$ 0.7
Aquion, Inc
Related Party Transaction [Line Items]
Purchase from related party	0.2
Outstanding payables to related party	$ 0.2		$ 0.2