Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025	Jun. 30, 2025	Dec. 31, 2024
Summary of Significant Accounting Policies
Restricted cash, noncurrent	$ 14,144	$ 10,227	$ 6,484	$ 0
Asset Pledged as Collateral \| DOE Loan & Term Facility
Summary of Significant Accounting Policies
Restricted cash	75,200	59,100
Restricted cash, noncurrent	14,100	10,200
Asset Pledged as Collateral \| Construction of Charging Stations
Summary of Significant Accounting Policies
Restricted cash	400	400
Asset Pledged as Collateral \| Credit Card Agreement
Summary of Significant Accounting Policies
Restricted cash	$ 200	$ 200

Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.