Summary of Significant Accounting Policies (Tables)

6 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Shares Used in Computing Basic and Diluted Earnings Per Share

Shares used in computing basic and diluted earnings per share are as follows:

	Three Months Ended March 31,		Six Months Ended March 31,
	2018	2017	2018	2017
Denominator (thousands of shares):
Weighted-average common shares outstanding — basic	173,570	173,624	173,617	173,567
Incremental shares issuable for stock options and awards (a)	2,780	3,512	3,029	3,409
Weighted-average common shares outstanding — diluted	176,350	177,136	176,646	176,976

(a) For the three and six months ended March 31, 2018, there were 2,486 shares associated with outstanding stock option awards that were not included in the computation of diluted earnings per share above because their effect was antidilutive. For the three and six months ended March 31, 2017, there were no such antidilutive shares.