POSTRETIREMENT BENEFITS AND EMPLOYEE STOCK OWNERSHIP PLAN - FAIR VALUE OF PLAN ASSETS - ADDITIONAL INFORMATION (Details) - Pension Plan - USD ($) $ in Millions |
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2014 |
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| Defined Benefit Plan Disclosure [Line Items] | ||||||||
| Defined Benefit Plan, Fair Value of Plan Assets | [1] | $ 10,269 | $ 10,605 | $ 11,098 | ||||
| Fair Value, Inputs, Level 2 | Cash and Cash Equivalents | ||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||
| Defined Benefit Plan, Fair Value of Plan Assets | 262 | 266 | ||||||
| Fair Value, Inputs, Level 3 | Other Assets | ||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||
| Defined Benefit Plan, Fair Value of Plan Assets | [2] | $ 128 | $ 123 | |||||
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