Reconciliation of Total Assets Measured at Fair Value on Recurring Basis to Balance Sheet Presentation (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other	$ 2	$ 1
Recorded basis of investment components	135,630	139,004
Other Current and Long-term Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Less derivative net assets classified as other current and long-term assets	(282)	(202)
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net fair value of assets measured at fair value on a recurring basis	130,412	133,985
Cash	3,942	3,624
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common and preferred stock measured at fair value on a nonrecurring basis	999	1,073
Other investments measured at fair value on a nonrecurring basis	$ 557	$ 523