Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income/(Loss)	Noncontrolling Interest
Balance at beginning of period (in shares) at Jun. 30, 2018		327.0
Balance at beginning of period at Jun. 30, 2018	$ 6,059	$ 2,730	$ 4,645		$ (92)	$ 0
Treasury, balance at beginning of period (in shares) at Jun. 30, 2018				(18.0)
Treasury, balance at beginning of period at Jun. 30, 2018				$ (1,224)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	874					1
Net Income (Loss) Attributable to Parent	873
Other Comprehensive Income (Loss), Net of Tax	(31)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(31)				(31)
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(27)	$ (2)		$ (29)
Payments for Repurchase of Common Stock	(600)			$ (600)
Treasury shares acquired (in shares)				(11.0)
Dividends	(286)		(286)
Other	0		1			1
Balance at end of period (in shares) at Dec. 31, 2018		327.0
Balance at end of period at Dec. 31, 2018	6,043	$ 2,728	5,233		(123)	0
Treasury, balance at end of period (in shares) at Dec. 31, 2018				(29.0)
Treasury, balance at end of period at Dec. 31, 2018				$ (1,795)
Balance at beginning of period (in shares) at Sep. 30, 2018		327.0
Balance at beginning of period at Sep. 30, 2018	5,913	$ 2,590	5,097		(96)	0
Treasury, balance at beginning of period (in shares) at Sep. 30, 2018				(27.0)
Treasury, balance at beginning of period at Sep. 30, 2018				$ (1,678)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	281					1
Net Income (Loss) Attributable to Parent	280
Other Comprehensive Income (Loss), Net of Tax	(27)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(27)				(27)
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(21)	(18)		$ (3)
Payments for Repurchase of Common Stock	0	$ 120		$ (120)
Treasury shares acquired (in shares)				(2.0)
Dividends	(143)		(143)
Other	2		(1)			1
Balance at end of period (in shares) at Dec. 31, 2018		327.0
Balance at end of period at Dec. 31, 2018	$ 6,043	$ 2,728	5,233		(123)	0
Treasury, balance at end of period (in shares) at Dec. 31, 2018				(29.0)
Treasury, balance at end of period at Dec. 31, 2018				$ (1,795)
Balance at beginning of period (in shares) at Jun. 30, 2019	327.0	327.0
Balance at beginning of period at Jun. 30, 2019	$ 6,330	$ 2,763	5,434		(79)	2
Treasury, balance at beginning of period (in shares) at Jun. 30, 2019	(28.0)			28.0
Treasury, balance at beginning of period at Jun. 30, 2019	$ (1,790)			$ 1,790
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(4,701)					1
Net Income (Loss) Attributable to Parent	(4,702)
Other Comprehensive Income (Loss), Net of Tax	(24)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(24)				(24)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(30)	(11)		(41)
Payments for Repurchase of Common Stock	(350)	$ 0		$ (350)
Treasury shares acquired (in shares)				(7.3)
Dividends	(284)		(284)
Other	$ (1)		(1)			0
Balance at end of period (in shares) at Dec. 31, 2019	327.0	327.0
Balance at end of period at Dec. 31, 2019	$ 1,002	$ 2,752	449		(103)	3
Treasury, balance at end of period (in shares) at Dec. 31, 2019	(35.0)			(35.0)
Treasury, balance at end of period at Dec. 31, 2019	$ (2,099)			$ (2,099)
Balance at beginning of period (in shares) at Sep. 30, 2019		327.0
Balance at beginning of period at Sep. 30, 2019	903	$ 2,669	371		(101)	3
Treasury, balance at beginning of period (in shares) at Sep. 30, 2019				34.0
Treasury, balance at beginning of period at Sep. 30, 2019				$ 2,039
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	220					0
Net Income (Loss) Attributable to Parent	220
Other Comprehensive Income (Loss), Net of Tax	(2)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(2)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(23)	(13)		(10)
Payments for Repurchase of Common Stock	0	$ 70		$ (70)
Treasury shares acquired (in shares)				(1.0)
Dividends	(143)		(143)
Other	$ (1)		1			0
Balance at end of period (in shares) at Dec. 31, 2019	327.0	327.0
Balance at end of period at Dec. 31, 2019	$ 1,002	$ 2,752	$ 449		$ (103)	$ 3
Treasury, balance at end of period (in shares) at Dec. 31, 2019	(35.0)			(35.0)
Treasury, balance at end of period at Dec. 31, 2019	$ (2,099)			$ (2,099)