Fixed Assets - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Machinery and equipment		$ 390
Office furniture and equipment	$ 60	177
Leasehold improvements	43	192
Fixed assets, gross	103	759
Accumulated depreciation and amortization	(63)	(697)
Fixed assets, net, after accumulated amortization	40	62
Operating lease ROU assets, net	235	322
Total	275	384
Depreciation expense	152	$ 24
Demonstration Burners
Property, Plant and Equipment [Line Items]
Impairment of Machinery and Equipment	81
Machinery and Equipment capitalized	209
Accumulated depreciation	$ 128