Revenue - Estimated future revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($)
Revenue
Total estimated future revenue	$ 860,491
Sales of fuel cell systems
Revenue
Total estimated future revenue	$ 34,172
Sale of hydrogen installations and other infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Total estimated future revenue	$ 20,842
Sales of electrolyzers
Revenue
Total estimated future revenue	$ 223,797
Sales of engineered equipment
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Total estimated future revenue	$ 2,084
Services performed on fuel cell systems and related infrastructure
Revenue
Total estimated future revenue	128,523
Power purchase agreements
Revenue
Total estimated future revenue	340,744
Fuel delivered to customers and related equipment
Revenue
Total estimated future revenue	$ 66,093
Sales of cryogenic equipment and other
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Total estimated future revenue	$ 44,236
Maximum | Sales of fuel cell systems
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	2 years
Maximum | Sales of electrolyzers
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	2 years
Maximum | Services performed on fuel cell systems and related infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	10 years
Maximum | Power purchase agreements
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	10 years
Maximum | Fuel delivered to customers and related equipment
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	10 years
Minimum | Sales of fuel cell systems
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Minimum | Sales of electrolyzers
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Minimum | Services performed on fuel cell systems and related infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	5 years
Minimum | Power purchase agreements
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	5 years
Minimum | Fuel delivered to customers and related equipment
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	5 years