Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Outstanding share awards earned and issued at greater than the target number of shares			150.00%
Restricted Stock | Minimum
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Vesting period (in years)			1 year
Restricted Stock | Maximum
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Vesting period (in years)			3 years
2007 Plan
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Aggregate number of shares that may be awarded (in shares)	646,000		646,000
Vesting period (in years)			10 years
Outstanding share awards that may be awarded (in shares)	363,000		363,000
Share-based compensation expense (benefit)	$ 187	$ (810)	$ 345	$ (464)
Total unrecognized compensation cost related to performance and restricted shares	$ 1,315		$ 1,315
Period of recognized compensation cost (in years)			2 years
2007 Plan | Performance shares
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Performance period (in years)			3 years
Shares vested in period (in shares)			5,000
Performance shares paid for payroll costs (in shares)			2,000
Shares granted in period (in shares)			69,000
2007 Plan | Performance shares | Minimum
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Common shares earned pursuant to award (in shares)			0
2007 Plan | Performance shares | Maximum
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Common shares earned as percentage of initial target number shares awarded			150.00%
2007 Plan | Restricted Stock
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Shares granted in period (in shares)			38,000
2007 Plan | Restricted Stock | Non-Employee Directors
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Vesting period (in years)			1 year
Shares vested in period (in shares)			29,000
Shares granted in period (in shares)			33,000
Shares granted in period, grant date fair value (in dollars per share)			$ 8.05
2007 Plan | Performance and Restricted Shares
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Vesting period (in years)			3 years
Shares granted in period (in shares)			107,000
Shares granted in period, grant date fair value (in dollars per share)			$ 7.45