Summary of Significant Accounting Policies (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Summary of Significant Accounting Policies
Impairment Loss	$ 0
Upfront revenue recognized	$ 0
Operating lease maximum allowed extension percentage	75.00%
Fuel
Summary of Significant Accounting Policies
Estimated useful life	10 years
Hydrogen infrastructure
Summary of Significant Accounting Policies
Estimated useful life	20 years
Minimum
Summary of Significant Accounting Policies
Payment terms for fuel cells and its services	30 days
Extension period	5 years
Uptime of the fleet (as a percent)	97.00%
Intangible asset useful lives	5 years
Maximum
Summary of Significant Accounting Policies
Payment terms for fuel cells and its services	90 days
Extension period	10 years
Uptime of the fleet (as a percent)	98.00%
Intangible asset useful lives	10 years