Summary of Significant Accounting Policies - Revenue of Business Units (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 58,581	$ 54,006
Proterra Transit
Disaggregation of Revenue [Line Items]
Total revenue	35,381	42,204
Proterra Powered & Energy
Disaggregation of Revenue [Line Items]
Total revenue	$ 23,200	$ 11,802

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details