COMMITMENTS AND CONTINGENCIES Environmental Remediation Obligations (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jun. 30, 2011
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 132
Accrual for Environmental Loss Contingencies, Gross	142
Cass Lake, Minnesota
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 49	$ 46

Total costs accrued as of the balance sheet date for environmental loss contingencies.

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