Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Additional Information (Details)

v3.10.0.1
Commitments and Contingencies - Additional Information (Details) - USD ($)
$ in Millions
9 Months Ended
Aug. 08, 2018
May 04, 2018
Sep. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Other Commitments [Line Items]          
Letters of credit outstanding, amount     $ 15.5   $ 16.4
Purchase commitment     $ 159.6    
Letter of Credit | Minimum          
Other Commitments [Line Items]          
Letter of credit, fee percentage     2.50%    
Letter of Credit | Maximum          
Other Commitments [Line Items]          
Letter of credit, fee percentage     3.25%    
Settled litigation | Slovin et al. v. Sunrun Inc. and Clean Energy Experts, LLC          
Other Commitments [Line Items]          
Settlement amount, accrual       $ 5.5  
Settled litigation | Cohen, et al. v. Sunrun Inc., et al.          
Other Commitments [Line Items]          
Settlement amount, accrual   $ 1.9      
Settlement amount   32.0      
Settlement amount, funded by insurers   $ 30.1      
Settled litigation | Fink, et al. v. Sunrun Inc., et al.          
Other Commitments [Line Items]          
Settlement amount $ 2.5