INVESTMENTS IN JOINT VENTURES - Summary of Combined Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	May 28, 2017	May 29, 2016	May 31, 2015
Statement of Earnings
Total net sales	$ 3,357.7	$ 3,562.5	$ 3,466.5
Total gross margin	374.9	372.0	398.6
Total earnings after income taxes	162.1	149.3	179.6
Ardent Mills
Statement of Earnings
Total net sales	3,180.0	3,395.3	3,299.2
Total gross margin	340.3	339.2	365.3
Total earnings after income taxes	152.0	142.9	173.5
Balance Sheet
Current assets	937.2	988.4
Noncurrent assets	1,694.2	1,695.3
Current liabilities	388.9	507.7
Noncurrent liabilities	518.0	545.0
Others
Statement of Earnings
Total net sales	177.7	167.2	167.3
Total gross margin	34.6	32.8	33.3
Total earnings after income taxes	10.1	6.4	$ 6.1
Balance Sheet
Current assets	75.5	80.8
Noncurrent assets	12.2	10.5
Current liabilities	44.5	51.0
Noncurrent liabilities	$ 0.0	$ 0.0