Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 23, 2014	Feb. 24, 2013	Feb. 23, 2014	Feb. 24, 2013
Statement of Comprehensive Income [Abstract]
Change in fair value of marketable securities, tax	$ 0	$ 0	$ 0.1	$ 0.1
Change in fair value of derivatives, tax	1.3	1.0	3.4	(1.6)
Net unamortized gain arising during period, including amortization of unrecognized net actuarial loss, tax	$ 1.0	$ 1.1	$ 3.0	$ 3.2