Financial Instruments (Summary of estimated fair value of our long-term obligations and other short-term borrowings) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount	$ 5,492	$ 3,972
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	$ 5,521	$ 4,115