Restructuring - Restructuring Activities and Related Reserves (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]
Reserve balance	$ 2	$ 0	$ 0
Charges	3	9	12
Costs charged against assets		(6)
Cash paid	(1)	(1)
Reserve balance	4	2	4
Severance and Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	2	0	0
Charges	2	3
Cash paid	(1)	(1)
Reserve balance	3	2	3
Accelerated Depreciation on Assets [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance		0	0
Charges, Accelerated depreciation on assets		6
Costs charged against assets		$ (6)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Charges	1
Reserve balance	$ 1		$ 1