Financial Instruments (Summary of Estimated Fair Value of Our Long-Term Obligations and Other Short-Term Borrowings) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Jun. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 4,003	$ 3,972
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	$ 4,148	$ 4,115