Equity Incentive Plans (Restricted stock award and restricted stock unit award activity) (Details) - Restricted Stock Awards [Member] - C3J Stock Plan 2016 [Member]	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Shares
Outstanding at beginning of period (in shares) | shares	200,000
Granted (in shares) | shares	90,000
Outstanding at end of period (in shares) | shares	290,000
Weighted Avg Grant Date Fair Value
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 2.39
Granted (in dollars per share) | $ / shares	3.38
Outstanding at end of period (in dollars per share) | $ / shares	$ 2.70