Stock-based Compensation - Schedule of Total Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 6,379	$ 3,013	$ 12,403	$ 4,891
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	3,075	995	6,114	1,477
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	2,754	1,735	5,196	2,920
Location, Statement of Income, Balance [Axis]: us-gaap:SellingAndMarketingExpense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	358	174	733	317
Location, Statement of Income, Balance [Axis]: kdk:TruckAndFreightOperationsExpense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 192	$ 109	$ 360	$ 177