CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2016	Sep. 30, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value (USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	82,078,175	81,093,052
Common stock, shares outstanding	68,616,306	67,631,183
Treasury stock, shares	13,461,869	13,461,869