Equity Securities and Stock-Based Compensation (Details) $ in Thousands, shares in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2015 shares	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Treasury stock and related deferred compensation obligation at fair value	$ 1,900			$ 1,900
Amount that the fair values of treasury stock and related deferred compensation obligation exceed the carrying values at cost	700			700
Stock-based compensation	800		$ 700	1,521	$ 1,339
Total compensation cost related to unvested awards not yet recognized	$ 4,100			$ 4,100
2010 Incentive Compensation Plan
Board approved share-based award grants to officers, employees, and directors (in shares) | shares		0.3
Awards granted vesting period		3 years
Factor applied to cash interest expense in the calculation of the 12-month adjusted EBITDA target for determination of vesting		1.5