Business Segments (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment							2
Total revenues	$ 9,019			$ 10,514			$ 27,860	$ 34,584
Depreciation	2,266			2,307			6,802	6,892
Loss from operations before equity income	(2,433)			(3,254)			(7,038)	(4,180)
Net equity income from foreign joint ventures' operations	573			135			1,347	135
Income (loss) from operations	(1,860)			(3,119)			(5,691)	(4,045)
Net loss	(2,133)	$ (3,463)	$ (1,050)	(3,355)	$ (1,038)	$ (559)	(6,646)	(4,952)
Total assets	79,084						79,084		$ 90,326
LNG
Segment Reporting Information [Line Items]
Total revenues	7,667			9,143			24,222	33,213
Depreciation	2,237			2,277			6,706	6,862
Loss from operations before equity income	(2,179)			(2,988)			(5,909)	(3,914)
Net equity income from foreign joint ventures' operations	0			0			0	0
Income (loss) from operations	(2,179)			(2,988)			(5,909)	(3,914)
Net loss	(2,458)			(3,209)			(6,678)	(4,806)
Total assets	65,582						65,582		75,883
Power Delivery
Segment Reporting Information [Line Items]
Total revenues	1,352			1,371			3,638	1,371
Depreciation	29			30			96	30
Loss from operations before equity income	(254)			(266)			(1,129)	(266)
Net equity income from foreign joint ventures' operations	573			135			1,347	135
Income (loss) from operations	319			(131)			218	(131)
Net loss	325			$ (146)			32	$ (146)
Total assets	$ 13,502						$ 13,502		$ 14,443
Bomay
Segment Reporting Information [Line Items]
Ownership percentage	40.00%						40.00%