Net Income (Loss) Per Share - Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator: Basic and Diluted
Net income	$ 2,792	$ 6,602	$ 1,858	$ 24,702
Dividends paid	(2,748)	(2,738)	(8,240)	(8,214)
Undistributed income (loss)	$ 44	$ 3,864	$ (6,382)	$ 16,488
Percentage allocated to common shares	99.00%	99.10%	99.00%	99.10%
Undistributed income (loss) allocated to common shares	$ 44	$ 3,829	$ (6,321)	$ 16,339
Dividends paid on common shares outstanding	2,721	2,713	8,160	8,140
Net income available to common shares	$ 2,765	$ 6,542	$ 1,839	$ 24,479
Denominator: Basic and Diluted
Weighted average common shares outstanding	12,370,039	12,333,550	12,358,609	12,330,994
Adjustment for dilutive potential common shares	2,278	13,244	4,761	12,678
Weighted average shares - Diluted	12,372,317	12,346,794	12,363,370	12,343,672
Basic net income per share (in dollars per share)	$ 0.22	$ 0.53	$ 0.15	$ 1.99
Diluted net income per share (in dollars per share)	$ 0.22	$ 0.53	$ 0.15	$ 1.98