Accrued Dividends Payable And Dividends per Common Share (Narrative) (Details) $ in Millions	9 Months Ended
	Feb. 25, 2017 USD ($)
Earnings Per Share Reconciliation [Abstract]
Percentage of net income loss used to compute accrued dividends	33.33%
Number of days after first, second and third quarter dividends paid	60 days
Number of days after fourth quarter dividends paid	65 days
Number of days dividends paid following record date	15 days
Cumulative loss to be recovered prior to paying dividend	$ (50.2)