Retirement and Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan cost			$ 4	$ 2	$ 2
Contributions capitalized			4	2	2
Defined benefit plan, benefit obligation, payment for settlement		$ 38
Settlement (gain) loss			2
Other comprehensive (income) loss, defined benefit plan, after tax and reclassification adjustment, attributable to parent			(9)	31	13
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement (gain) loss			2	(1)	2
Transfer from plan assets	$ 14		14	0
Settlements			58	40
Other comprehensive (income) loss, defined benefit plan, after tax and reclassification adjustment, attributable to parent			(16)	27
Employer contributions			0	0
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement (gain) loss			0	0	0
Transfer from plan assets			0		$ 0
Settlements			0	0
Other comprehensive (income) loss, defined benefit plan, after tax and reclassification adjustment, attributable to parent			7	4
Employer contributions			0	$ 1
Expected future benefit payment, after year five for next five years			$ 3