Summary of Business and Significant Accounting Principles - Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2019
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	39 years
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	6 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Vehicles and prototypes | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Vehicles and prototypes | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years