Net Income (Loss) Per Share/Unit - Computation of Basic and Diluted Net Loss Per Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income (loss) - Diluted	$ (20,534)	$ (27,984)	$ (61,747)	$ 40,228
Less: Dividends on preferred units	0	(890)	(1,491)	(2,631)
Net income (loss) attributable to common shareholders/unitholders - Basic	$ (20,534)	$ (28,874)	$ (63,238)	$ 37,597
Basic weighted-average common shares/units outstanding (in Units)	17,786	12,469	14,872	12,454
Effecting of dilutive securities:
Series A preferred units (in Units)	0	0	0	3,969
Restricted units (in Units)	0	0	0	148
Diluted weighted-average common shares/units outstanding (in Units)	17,786	12,469	14,872	16,571
Continuing Operations, Basic net income (loss) per common shares/unit (USD per Unit)	$ (1.15)	$ (2.32)	$ (4.25)	$ 3.02
Continuing Operations, Diluted net income (loss) per common unit (USD per Unit)	$ (1.15)	$ (2.32)	$ (4.25)	$ 2.43