Net Income (Loss) Per Share - Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator: Basic and Diluted
Net loss - Basic	$ (3,967)	$ 2,792	$ (6,529)	$ 1,858
Net loss - Diluted	(3,967)	2,792	(6,529)	1,858
Dividends paid	(2,752)	(2,748)	(8,257)	(8,240)
Undistributed loss - Basic	(6,719)	44	(14,786)	(6,382)
Undistributed loss - Diluted	$ (6,719)	$ 44	$ (14,786)	$ (6,382)
Percentage allocated to common shares	100.00%	99.00%	100.00%	99.00%
Undistributed income (loss) allocated to common shares - Basic	$ (6,719)	$ 44	$ (14,786)	$ (6,321)
Undistributed income (loss) allocated to common shares - Diluted	(6,719)	44	(14,786)	(6,321)
Dividends paid on common shares outstanding	2,725	2,721	8,176	8,160
Net income (loss) available to common shares - Basic	(3,994)	2,765	(6,610)	1,839
Net income (loss) available to common shares - Diluted	$ (3,994)	$ 2,765	$ (6,610)	$ 1,839
Denominator: Basic and Diluted
Weighted average common shares outstanding - Basic	12,400,522	12,370,039	12,394,350	12,358,609
Adjustment for dilutive potential common shares		2,278		4,761
Weighted average shares - Diluted	12,400,522	12,372,317	12,394,350	12,363,370
Basic net income (loss) per share (in dollars per share)	$ (0.32)	$ 0.22	$ (0.53)	$ 0.15
Diluted net income (loss) per share (in dollars per share)	$ (0.32)	$ 0.22	$ (0.53)	$ 0.15