Summary of Significant Accounting Policies (Tables)

6 Months Ended

Mar. 31, 2017

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,
	2017	2016	2017	2016
Denominator (thousands of shares):
Weighted-average common shares outstanding — basic	173,624	172,619	173,567	172,733
Incremental shares issuable for stock options and awards (a)	3,512	2,226	3,409	2,220
Weighted-average common shares outstanding — diluted	177,136	174,845	176,976	174,953

(a) See “Adoption of New Accounting Standard — Employee Share-based Payments” below for the impact on the calculation of diluted shares for the three and six months ended March 31, 2017 resulting from the adoption of new accounting guidance regarding share-based payments.