Controlled Launch (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) item	Mar. 31, 2021 USD ($)
Controlled Launch [Abstract]
Number of KOLs | item	70
Number of patients participating in procedure	40 or 50
Program expenses	$ 0.3	$ 0.1
Revenue recognized	$ 0.3