INVESTMENTS IN JOINT VENTURES - Summary of Combined Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	May 27, 2018	May 28, 2017	May 29, 2016
Statement of Earnings
Total net sales	$ 3,542.9	$ 3,357.7	$ 3,562.5
Total gross margin	421.3	374.9	372.0
Total earnings after income taxes	207.1	162.1	149.3
Ardent Mills
Statement of Earnings
Total net sales	3,344.1	3,180.0	3,395.3
Total gross margin	386.5	340.3	339.2
Total earnings after income taxes	197.0	152.0	142.9
Balance Sheet
Current assets	974.6	937.2
Noncurrent assets	1,675.7	1,694.2
Current liabilities	355.6	388.9
Noncurrent liabilities	510.9	518.0
Others
Statement of Earnings
Total net sales	198.8	177.7	167.2
Total gross margin	34.8	34.6	32.8
Total earnings after income taxes	10.1	10.1	$ 6.4
Balance Sheet
Current assets	76.4	75.5
Noncurrent assets	15.5	12.2
Current liabilities	37.5	44.5
Noncurrent liabilities	$ 0.1	$ 0.0