Accrued Dividends Payable and Dividends per Common Share (Schedule of Dividends) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Feb. 27, 2021	Feb. 29, 2020	Feb. 27, 2021	Feb. 29, 2020
Class of Stock [Line Items]
Net income (loss) attributable to Cal-Maine Foods, Inc.		$ 13,548	$ 13,749	$ 6,304	$ (42,072)
Cumulative losses to be recovered prior to payment of divided at beginning of period		(8,614)	(75,582)	(1,370)	(19,761)
Net income attributable to Cal-Maine Foods, Inc. available for dividend		4,934	$ 0	$ 4,934	$ 0
1/3 of net income attributable to Cal-Maine Foods, Inc. available for dividend		$ 1,645
Stock outstanding (shares)		48,856		48,856
Dividends per common share	[1]	$ 0.034
Common Stock [Member]
Class of Stock [Line Items]
Stock outstanding (shares)		44,056		44,056
Class A Common Stock [Member]
Class of Stock [Line Items]
Stock outstanding (shares)		4,800		4,800

[1] Dividends per common share   = 1/3 of Net   income (loss) attributable to   Cal-Maine Foods, Inc. available   for dividend ÷ Total   common stock outstanding (shares).