Stock-based Compensation - Schedule of Stock Options and SSARs Outstanding and Related Activity (Details) - Stock Options - $ / shares	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Shares [Roll Forward]
Outstanding at beginning of period (in shares)	593,753	672,669	643,907
Granted (in shares)	25,230	29,410	125,449
Exercised (in shares)	(8,411)	(2,313)	0
Expired (in shares)	(61,967)	(84,976)	(86,606)
Canceled (in shares)	0	(480)	0
Forfeited (in shares)	(15,553)	(20,557)	(10,081)
Outstanding at end of period (in shares)	533,052	593,753	672,669
Exercisable at end of period (in shares)	479,538	476,606	503,594
Vested or expected to vet in the future (in shares)	533,052	585,186	672,669
Weighted-Average Exercise Price [Roll Forward]
Outstanding at beginning or period (in dollars per share)	$ 14.76	$ 16.49	$ 18.13
Granted (in dollars per share)	19.99	12.50	9.19
Exercised (in dollars per share)	7.52	10.80	0.00
Expired (in dollars per share)	23.19	28.45	19.70
Canceled (in dollars per share)	0.00	23.65	0.00
Forfeited (in dollars per share)	10.46	11.97	10.98
Outstanding at end of period (in dollars per share)	14.26	14.76	16.49
Exercisable at end of period (in dollars per share)	14.03	15.91	17.76
Vested or expected to vest in the future (in dollars per share)	$ 14.26	$ 14.83	$ 16.49