Stock Plans (Schedule of net cash proceeds from the exercise of stock options less shares used for withholding taxes and the intrisic value of options exercised) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 26, 2012	Aug. 28, 2011
Stock Plans [Abstract]
Net cash proceeds	$ 39.0	$ 24.0
Intrinsic value of options exercised	$ 58.2	$ 13.8