Stock-based Compensation - Schedule of Stock Options and SSARs Outstanding and Related Activity (Details) - Stock Options - $ / shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Shares [Roll Forward]
Outstanding at beginning of period (in shares)	672,669	643,907	650,223
Granted (in shares)	29,410	125,449	0
Exercised (in shares)	(2,313)	0	(1,209)
Expired (in shares)	(84,976)	(86,606)	0
Canceled (in shares)	(480)	0	0
Forfeited (in shares)	(20,557)	(10,081)	(5,107)
Outstanding at end of period (in shares)	593,753	672,669	643,907
Exercisable at end of period (in shares)	476,606	503,594	491,029
Vested or expected to vet in the future (in shares)	585,186	672,669	643,877
Weighted-Average Exercise Price [Roll Forward]
Outstanding at beginning or period (in dollars per share)	$ 16.49	$ 18.13	$ 18.12
Granted (in dollars per share)	12.50	9.19	0.00
Exercised (in dollars per share)	10.80	0.00	12.07
Expired (in dollars per share)	28.45	19.70	0.00
Canceled (in dollars per share)	23.65	0.00	0.00
Forfeited (in dollars per share)	11.97	10.98	19.05
Outstanding at end of period (in dollars per share)	14.76	16.49	18.13
Exercisable at end of period (in dollars per share)	15.91	17.76	18.40
Vested or expected to vest in the future (in dollars per share)	$ 14.83	$ 16.49	$ 18.13