Equity - Schedule of Stock-based Compensation Expense - by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 922	$ 1,045	$ 1,825	$ 1,846
Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1	4	2	9
Restricted stock units and awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	501	552	932	928
Performance stock units and awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	269	363	586	655
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	84	46	173	93
Outside director equity awards and fees in common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 67	$ 80	$ 132	$ 161