Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ 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, 2019		327,000
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				(28,000)
Treasury, balance at beginning of period at Jun. 30, 2019				$ (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, Shares, Share-based Payment Arrangement, after Forfeiture		0		0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(30)	$ (11)		$ (41)
Payments for Repurchase of Common Stock	(350)
Treasury shares acquired (in shares)				(7,000)
Dividends	(284)		(284)
Other	(1)		1			0
Balance at end of period (in shares) at Dec. 31, 2019		327,000
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				(35,000)
Treasury, balance at end of period at Dec. 31, 2019				$ (2,099)
Treasury Stock, Value, Acquired, Cost Method	(350)			$ (350)
Balance at beginning of period (in shares) at Sep. 30, 2019		327,000
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				(34,000)
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)				(2)
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture		0		0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(23)	$ (13)		$ (10)
Payments for Repurchase of Common Stock		$ (70)
Treasury shares acquired (in shares)				(1,000)
Dividends	(143)		(143)
Other	(1)		1			0
Balance at end of period (in shares) at Dec. 31, 2019		327,000
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				(35,000)
Treasury, balance at end of period at Dec. 31, 2019				$ (2,099)
Treasury Stock, Value, Acquired, Cost Method	$ 0			$ (70)
Balance at beginning of period (in shares) at Jun. 30, 2020	327,000	327,000
Balance at beginning of period at Jun. 30, 2020	$ 1,792	$ 2,789	1,170		(104)	3
Treasury, balance at beginning of period (in shares) at Jun. 30, 2020	(34,000)			35,000
Treasury, balance at beginning of period at Jun. 30, 2020	$ (2,066)			$ 2,066
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	377					1
Net Income (Loss) Attributable to Parent	376
Other Comprehensive Income (Loss), Net of Tax	51
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 51				51
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture	2,000	0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	$ (46)	$ (11)		$ (57)
Payments for Repurchase of Common Stock	0
Dividends	(289)		(289)
Other	$ 2		2			0
Balance at end of period (in shares) at Dec. 31, 2020	327,000	327,000
Balance at end of period at Dec. 31, 2020	$ 1,975	$ 2,778	1,255		(53)	4
Treasury, balance at end of period (in shares) at Dec. 31, 2020	(33,000)			(33,000)
Treasury, balance at end of period at Dec. 31, 2020	$ (2,009)			$ (2,009)
Balance at beginning of period (in shares) at Sep. 30, 2020		327,000
Balance at beginning of period at Sep. 30, 2020	1,425	$ 2,760	771		(87)	3
Treasury, balance at beginning of period (in shares) at Sep. 30, 2020				33,000
Treasury, balance at beginning of period at Sep. 30, 2020				$ 2,022
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	630					1
Net Income (Loss) Attributable to Parent	629
Other Comprehensive Income (Loss), Net of Tax	34
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	34
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture		0		0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(30)	$ (17)		$ (13)
Dividends	(144)		(144)
Other	$ 0	$ 1	(1)			0
Balance at end of period (in shares) at Dec. 31, 2020	327,000	327,000
Balance at end of period at Dec. 31, 2020	$ 1,975	$ 2,778	$ 1,255		$ (53)	$ 4
Treasury, balance at end of period (in shares) at Dec. 31, 2020	(33,000)			(33,000)
Treasury, balance at end of period at Dec. 31, 2020	$ (2,009)			$ (2,009)