STOCKHOLDERS' EQUITY - Changes in AOCI (Details) $ in Millions	9 Months Ended
	Feb. 23, 2020 USD ($)
Changes in AOCI:
Balance at the beginning of the period	$ (4.6)
Balance at the end of the period	270.4
Accumulated Other Comprehensive Loss
Changes in AOCI:
Balance at the beginning of the period	(25.3)
Other comprehensive income before reclassifications, net of tax	(15.7)
Amounts reclassified out of AOCI, net of tax	0.4
Net current-period other comprehensive income (loss)	(15.3)
Balance at the end of the period	(40.6)
Foreign Currency Translation Gains (Losses)
Changes in AOCI:
Balance at the beginning of the period	(20.3)
Other comprehensive income before reclassifications, net of tax	(15.7)
Net current-period other comprehensive income (loss)	(15.7)
Balance at the end of the period	(36.0)
Pension and Post-Retirement Benefits
Changes in AOCI:
Balance at the beginning of the period	(5.0)
Amounts reclassified out of AOCI, net of tax	0.4
Net current-period other comprehensive income (loss)	0.4
Balance at the end of the period	$ (4.6)