Accrued Dividends Payable and Dividends per Common Share (Schedule of Dividends) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 28, 2020	Nov. 30, 2019	Nov. 28, 2020	Nov. 30, 2019
Class of Stock [Line Items]
Net income (loss) attributable to Cal-Maine Foods, Inc.	$ 12,155	$ (10,061)	$ (7,244)	$ (55,821)
Cumulative losses to be recovered prior to payment of divided at beginning of period	(20,769)	(65,521)	(1,370)	(19,761)
Net income (loss) attributable to Cal-Maine Foods, Inc.	$ 0	$ 0	$ 0	$ 0
Common stock, shares outstanding (in shares)	48,768		48,768
Dividends per common share (in dollars per share)	$ 0
Common Stock
Class of Stock [Line Items]
One third of net income attributable to parent	$ 0
Common stock, shares outstanding (in shares)	43,968		43,968
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares outstanding (in shares)	4,800		4,800