Intangible Assets and Goodwill - Gross Carrying Amount (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Gross Carrying Amount	$ 235,352	$ 235,742
Accumulated Amortization	(42,175)	(28,017)
Total	$ 193,177	$ 207,725
Acquired technology
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period	14 years	14 years
Gross Carrying Amount	$ 104,159	$ 104,221
Accumulated Amortization	(18,471)	(12,754)
Total	$ 85,688	$ 91,467
Dry stack electrolyzer technology
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period	10 years	10 years
Gross Carrying Amount	$ 29,000	$ 29,000
Accumulated Amortization	(4,592)	(2,417)
Total	$ 24,408	$ 26,583
Customer relationships trade name and other
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period	13 years	13 years
Gross Carrying Amount	$ 102,193	$ 102,521
Accumulated Amortization	(19,112)	(12,846)
Total	$ 83,081	$ 89,675