Note 3 - Discontinued Operations and Sale of a Business (Details Textual) - Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] - Orbital Gas Systems Limited [Member] $ in Thousands, £ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 GBP (£)	Mar. 31, 2021 USD ($)
Disposal Group, Including Discontinued Operation, Assets Held-for-sale Impairment		$ 9,200
Investment, Expected Net Realizable Value			£ 3	$ 4,100
Cash Provided by (Used in) Operating Activities, Discontinued Operations	$ 500
Cash Provided by (Used in) Investing Activities, Discontinued Operations	$ 10