Stock-Based Compensation - Summary of Stock-Based Compensation Expense Additional Details (Details) - Warrants	1 Months Ended
	Aug. 31, 2017 USD ($) solar_energy_system_install vesting_increment $ / shares shares	Jun. 30, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant, term	40 months
Warrant, number purchased | shares	11,793,355
Warrant, exercise price (in dollars per share) | $ / shares	$ 0.01
Warrant, vesting percentage	50.05%
Warrant, milestone one, solar energy systems | solar_energy_system_install	30,000
Warrant, milestone, marketing and sales dollars | $	$ 10,000,000.0
Warrant, vesting term | vesting_increment	5
Warrant, milestone two, solar energy systems | solar_energy_system_install	6,000
Warrant, vested | shares		0