Acquisitions - Allocation Of Purchase Price (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jun. 22, 2020	Jun. 18, 2020
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Deferred tax liability, net	$ (5,900)
Giner ELX, Inc
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Accounts receivable		$ 1,237
Inventory		4,108
Prepaid expenses and other assets		669
Property, Plant and equipment.		596
Identifiable intangibles		29,930
Accounts payable, accrued expenses, deferred revenue and finance obligations		(1,621)
Deferred revenue		(2,350)
Deferred tax liability, net		(5,889)
Total net assets acquired, excluding goodwill		$ 26,680
United Hydrogen Group Inc
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Accounts receivable			$ 444
Inventory			89
Prepaid expenses and other assets			1,152
Property, Plant and equipment.			41,244
Leased property			796
Identifiable intangibles			2,338
Long-term debt			(11,336)
Unfavorable customer contract			(15,757)
Accounts payable, accrued expenses, deferred revenue and finance obligations			(4,631)
Total net assets acquired, excluding goodwill			$ 14,339