CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Purchase of treasury stock (in shares)	336,386	135,147
Issuance of treasury stock (in shares)	326,827	215,058
Cancellations of treasury stock (in shares)	5,214	2,640
Dividends, per share (in dollars per share)	$ 0.38	$ 0.34