Dividends and Share Repurchases (Details) - $ / shares		3 Months Ended		6 Months Ended
	Feb. 12, 2016	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Dividends [Abstract]
Dividends declared (in dollars per share)	$ 0.14
Cash dividends per share (in dollars per share)		$ 0.14	$ 0.13	$ 0.27	$ 0.28
Stock repurchased (in shares)				1,639,442	2,500,018
Average cost per share (in dollars per share)				$ 21.05	$ 21.21
Remaining shares authorized to be repurchased (in shares)		2,138,706		2,138,706