Maturities of lease liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating Leases, Year Ending June 30, 2020 (excluding the three months ended September 30, 2019)	$ 1,303
Operating Leases, Year Ending June 30, 2021	1,536
Operating Leases, Year Ending June 30, 2022	1,335
Operating Leases, Year Ending June 30, 2023	1,139
Operating Leases, Year Ending June 30, 2024	940
Operating Leases, Thereafter	2,918
Operating Leases, Total lease payments	9,171
Operating Leases, Less imputed interest	(961)
Operating Leases	8,210	$ 7,703
Finance Leases, Year Ending June 30, 2020 (excluding the three months ended September 30, 2019)	532
Finance Leases, Year Ending June 30, 2021	727
Finance Leases, Year Ending June 30, 2022	740
Finance Leases, Year Ending June 30, 2023	746
Finance Leases, Year Ending June 30, 2024	756
Finance Leases, Thereafter	6,779
Finance Leases, Total lease payments	10,280
Finance Leases, Less imputed interest	(2,415)
Finance Leases	$ 7,865	$ 6,574