Stock-based Compensation - Schedule of Nonvested Stock Awards and Performance Shares (Details) - Nonvested Stock Awards and Performance Shares - $ / shares	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Shares [Roll Forward]
Beginning of period (in shares)	746,567	280,416	323,335
Granted (in shares)	410,192	595,567	99,413
Vested (in shares)	(64,719)	(113,320)	(126,124)
Forfeited (in shares)	(135,757)	(16,096)	(16,208)
End of period (in shares)	956,283	746,567	280,416
Weighted-Average Grant Date Fair Value ($ per share) [Roll Forward]
Beginning of period (in dollars per share)	$ 15.76	$ 12.32	$ 19.61
Granted (in dollars per share)	19.01	18.68	10.95
Vested (in dollars per share)	15.96	22.55	27.59
Forfeited (in dollars per share)	7.77	15.93	30.57
End of period (in dollars per share)	$ 18.27	$ 15.76	$ 12.32