Shareholders' Equity (Deficiency) (Shareholders' Equity Activity) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning balance	$ 496		$ 937
Net Income (Loss)	(74)		(110)	$ (110)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	4
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders			2
Other Comprehensive Income (Loss), Net of Tax		$ 0	(4)
Balance, ending balance	426	426	821
Capital in Excess of Par Value
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning balance	2,904		2,897
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	4
Balance, ending balance		2,908	2,897
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning balance	(2,397)		(1,947)
Net Income (Loss)	(80)		(116)
Balance, ending balance		(2,477)	(2,063)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning balance	(35)		(43)
Other Comprehensive Income (Loss), Net of Tax		0	(4)
Balance, ending balance		(35)	(47)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning balance	24		30
Net Income (Loss)	$ 6		6
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders			2
Balance, ending balance		$ 30	$ 34