Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Feb. 26, 2017	Feb. 28, 2016
Supplemental Cash Flow Elements [Abstract]
Interest paid, net of amounts capitalized	$ 24.9	$ 123.8
Income taxes paid, net of refunds	61.3	105.8
Increase in land, buildings and equipment through accrued purchases	25.2	14.1
Net book value of assets distributed in Four Corners separation, net of deferred tax liabilities	$ 0.0	$ 750.4