Pass-through Financing Obligations (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Property Subject to or Available for Operating Lease [Line Items]
Customer agreement, initial term	22 years
Solar energy systems, gross	$ 707.0	$ 715.5
Depreciation on lease	138.0	$ 120.2
Lease termination	18.1
Debt extinguishment expense	$ (6.3)
Minimum
Property Subject to or Available for Operating Lease [Line Items]
Solar energy systems, initial term	7 years
Customer agreement, initial term	20 years
Maximum
Property Subject to or Available for Operating Lease [Line Items]
Solar energy systems, initial term	22 years
Customer agreement, initial term	25 years