Stock-Based Compensation - Schedule of Stock Options and SSARs Outstanding and Related Activity (Details) - Stock Options - $ / shares	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Shares [Roll Forward]
Outstanding at beginning of period (in shares)	533,052	593,753	672,669
Granted (in shares)	30,782	25,230	29,410
Exercised (in shares)	(31,450)	(8,411)	(2,313)
Expired (in shares)	0	(61,967)	(84,976)
Canceled (in shares)	0	0	(480)
Forfeited (in shares)	(8,630)	(15,553)	(20,557)
Outstanding at end of period (in shares)	523,754	533,052	593,753
Exercisable at end of period (in shares)	470,501	479,538	476,606
Vested or expected to vet in the future (in shares)	521,362	533,052	585,186
Weighted-Average Exercise Price [Roll Forward]
Outstanding at beginning or period (in dollars per share)	$ 14.26	$ 14.76	$ 16.49
Granted (in dollars per share)	10.23	19.99	12.50
Exercised (in dollars per share)	10.00	7.52	10.80
Expired (in dollars per share)	0.00	23.19	28.45
Canceled (in dollars per share)	0.00	0.00	23.65
Forfeited (in dollars per share)	10.45	10.46	11.97
Outstanding at end of period (in dollars per share)	14.34	14.26	14.76
Exercisable at end of period (in dollars per share)	14.42	14.03	15.91
Vested or expected to vest in the future (in dollars per share)	$ 14.36	$ 14.26	$ 14.83