Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Denominator (thousands of shares):
Average common shares outstanding for basic computation (in shares)	115,173	113,709	114,996	113,416
Incremental shares issuable for stock options and awards (in shares)	1,574	1,490	1,530	1,413
Average common shares outstanding for diluted computation (in shares)	116,747	115,199	116,526	114,829