Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) Agency $ / shares shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) Agency $ / shares shares
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 883,949		$ 4,432,000
Current exercise price of warrants | $ / shares	$ 4.45		$ 4.45
Accounts receivable	$ 8,500		$ 661,352
Allowance for Doubtful Trade Receivable, Current	$ 0		$ 0
Number of Government Agencies | Agency	2		2
Notes Receivable	$ 823,848		$ 834,491
Allowance for Notes Receivable, Current	571,000		471,000
Inventory, net	431,470		494,158
Inventory Valuation Reserves	0		0
Inventory Deposits	$ 801,204		$ 935,204
Stock options outstanding | shares	13,904,436		25,617,338
Stock warrants outstanding | shares	7,556,323		7,556,323
Impairment of Long-Lived Assets Held-for-use	$ 0		$ 0
Research and Development Expense	0	$ 147,656
Property, Plant, and Equipment, Threshold for Capitalization of Purchases	$ 2,000
Property, Plant, and Equipment Other than Leasehold Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Property, Plant, and Equipment Other than Leasehold Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	5 years
California Government Agencies [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable			$ 15,000
Blue Bird Corporation [Member] | Electric Drivetrain [Member]
Summary Of Significant Accounting Policies [Line Items]
Amount to be received for each electric drivetrain ordered	$ 5,000
Fair Value, Measurements, Recurring [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0
January 2018 Public Offering [Member]
Summary Of Significant Accounting Policies [Line Items]
Current exercise price of warrants | $ / shares	$ 4.50