Commitments and Contingencies - Additional Information (Detail) $ in Millions		1 Months Ended
	Oct. 16, 2018 USD ($) Director	Oct. 05, 2016 Plaintiff	Sep. 30, 2018 USD ($)
Commitments And Contingencies [Line Items]
Letters Of Credit Outstanding Amount | $			$ 143.1
Subsequent Event [Member]
Commitments And Contingencies [Line Items]
Civil penalties amount payable | $	$ 20.0
Number of independent directors to be appointed | Director	1
Number of additional independent directors to be appointed | Director	2
Subsequent Event [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Independent director serving period	3 years
Lawsuit in the Court of Chancery of the State of Delaware by purported stockholders of Tesla challenging SolarCity Acquisition [Member]
Commitments And Contingencies [Line Items]
Number of lawsuits filed | Plaintiff		7