Restructuring Plans - Schedule of Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019
Restructuring And Related Activities [Abstract]
Balance at beginning of the year						$ 40
Severance expense, net of adjustments	$ 217	$ 38	$ 35	$ 173	$ 864	217	$ 1,110
Cash payments						(155)	(1,070)
Balance at the end of the year		$ 40				$ 102	$ 40