Revenue, Deferred Revenue and Related Costs (Details) $ / shares in Units, $ in Thousands, shares in Millions		1 Months Ended	3 Months Ended
	Aug. 02, 2017 USD ($) $ / shares shares	Aug. 31, 2017 item	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Oxide plant lease			$ 1,932	$ 1,637
Lease related costs			597	503
Amortized income related to the upfront cash payment				100
Oxide Plant
Oxide plant lease			1,900	1,600
Lease related costs			600	$ 500
Renewal term	2 years
Expected lease proceeds	$ 1,000		100
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 | item		1
Deferred revenue			$ 500