Summary of Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Denominator (thousands of shares):
Average common shares outstanding for basic computation	173,136	173,055	173,060	172,682
Incremental shares issuable for stock options and awards	2,444	2,517	2,605	2,415
Average common shares outstanding for diluted computation	175,580	175,572	175,665	175,097