CONSOLIDATED STATEMENT OF EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Shares repurchased (in shares)	23,897	326,421	345,081
Common stock, par value (in dollars per share)	$ 0.01	$ 3.0
Dividends paid (in dollars per share)	$ 0.18	$ 0	$ 0