Non-designated Derivative Gains (Losses) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	$ (93)	$ (166)	$ (346)	$ (215)
Foreign Exchange Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	(64)	(115)	(248)	(120)
Equity Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	(11)	(42)	(89)	(84)
Interest Rate Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	(18)	8	(9)	2
Credit Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	0	1	0	5
Other Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Changes in fair value of derivatives not designated as hedges	$ 0	$ (18)	$ 0	$ (18)