Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Aug. 29, 2020	Aug. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (19,399)	$ (45,721)
Other comprehensive income (loss), before tax:
Unrealized holding gain (loss) on available-for-sale securities, net of reclassification adjustments	468	(584)
(Increase) decrease in accumulated post-retirement benefits obligation, net of reclassification adjustments	114	(142)
Income tax (benefit) expense related to items of other comprehensive income	354	(442)
Other comprehensive income (loss), net of  tax	(19,045)	(46,163)
Comprehensive loss	0	39
Less: Comprehensive income attributable to the noncontrolling interest	$ (19,045)	$ (46,202)