Dividends and Share Repurchases (Details) - $ / shares			3 Months Ended		9 Months Ended
	Jul. 23, 2018	May 25, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Dividends Payable [Line Items]
Cash dividends per share (in dollars per share)		$ 0.17	$ 0.17	$ 0.15	$ 0.49	$ 0.69
Stock repurchased (in shares)			1,224,384
Average cost per share (in dollars per share)			$ 32.64
Warrants outstanding (in shares)			107,617		107,617
Remaining shares authorized to be repurchased (in shares)			2,855,765		2,855,765
2008 Troubled Asset Relief Program
Dividends Payable [Line Items]
Stock issued during period (in shares)			2,329
Subsequent Event
Dividends Payable [Line Items]
Dividends declared (in dollars per share)	$ 0.18