Revenue, Deferred Revenue and Related Costs (Details) $ / shares in Units, $ in Thousands, shares in Millions		1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 02, 2017 USD ($) $ / shares shares	Aug. 31, 2017 Right	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Oxide plant lease			$ 1,944	$ 1,900	$ 5,852	$ 5,267
Lease related costs			$ 594	$ 657	$ 1,804	1,685
Term of operating lease			5 years 8 months		5 years 8 months
Oxide Plant
Renewal term	2 years
Expected lease proceeds	$ 1,000				$ 200	$ 200
Gross proceeds from common stock sale	$ 1,000
Common stock issued (in shares) | shares	1.8
Sale price (in dollars per shares) | $ / shares	$ 0.55
Volume weighted average stock price period	30 days
Termination notice period		120 days
Number of rights of first refusal | Right		1
Deferred revenue			$ 400		$ 400