Benefit Plans (Summary of non-service cost (benefit) in the condensed consolidated statements of operations (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic defined benefits expense (reversal of expense), excluding service cost component	$ 3	$ (13)	$ 9	$ (41)
Insurance claims and policyholder's benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic defined benefits expense (reversal of expense), excluding service cost component	1	(3)	2	(11)
Other operating expenses
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic defined benefits expense (reversal of expense), excluding service cost component	$ 2	$ (10)	$ 7	$ (30)