Recent Accounting Pronouncements - Effect of Adoption To Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income	$ 103	$ 208	$ 282	$ 511
Deferred income tax charge (benefit)			(14)	2
Cash flows due to changes in other assets and other liabilities			(1)	(54)
OMFC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income	$ 103	208	282	511
Deferred income tax charge (benefit)			(14)	2
Cash flows due to changes in other assets and other liabilities			$ (1)	(53)
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income		209		510
Deferred income tax charge (benefit)				1
Cash flows due to changes in other assets and other liabilities				(52)
Previously Reported | OMFC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash flows due to changes in other assets and other liabilities				(51)
Revision of Prior Period, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income		$ (1)		1
Deferred income tax charge (benefit)				1
Cash flows due to changes in other assets and other liabilities				(2)
Revision of Prior Period, Adjustment | OMFC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash flows due to changes in other assets and other liabilities				$ (2)