Solar Energy Systems, net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Solar Energy Systems Disclosure [Abstract]
Depreciation expense	$ 139.2	$ 112.8	$ 87.7
Amortization of deferred grants	$ 7.8	$ 7.6	$ 13.0