Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill and Other Intangible Asset Balances

The following table presents goodwill and other intangible asset balances and adjustments to those balances for the years ended December 31, 2023 and 2022:

	Goodwill		Intangible Assets
(Dollars in Millions)	Net Carrying Amount		Cost		Accumulated Amortization		Net Carrying Amount		Total Goodwill and Other Intangible Assets - Net
Balance at December 31, 2021	$	276	$	180	$	(5)	$	175	$	451
Additions	43		18		—		18		61
Amortization	—		—		(10)		(10)		(10)
Balance at December, 31, 2022	$	319	$	198	$	(15)	$	183	$	502
Additions	6		8		—		8		14
Amortization	—		—		(10)		(10)		(10)
Balance at December, 31, 2023	$	325	$	206	$	(25)	$	181	$	506