Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Current assets:
Allowances for returns and doubtful accounts	$ 350,646	$ 338,245
Stockholders' equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	265,080,252	262,542,659
Common stock, shares outstanding	230,886,422	235,394,281
Treasury stock, shares held	34,193,830	27,148,378