Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Aug. 26, 2012	May 27, 2012
Allowance for doubtful accounts	$ 5.7	$ 5.9
Common stock, par value	$ 5	$ 5
Common stock, authorized	1,200,000,000	1,200,000,000
Common stock, issued	567,907,172	567,907,172
Treasury stock, common shares	162,076,397	160,294,748