Earnings Per Share (Details)	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share
Antidilutive potential common shares excluded in computation of diluted loss per share										700,000
Denominator for basic earnings per share (in shares)	98,000,000	99,300,000	100,400,000	104,800,000	110,000,000	110,200,000	113,400,000	114,000,000	100,618,000	111,875,000	117,396,000
Potential common shares (in shares)									1,300,000		900,000
Denominator for diluted earnings per share (in shares)	99,700,000	100,800,000	101,800,000	105,500,000	110,000,000	110,800,000	114,300,000	114,600,000	101,942,000	111,875,000	118,345,000