Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2023

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The components of net periodic benefit cost are as follows:

dollars in millions	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Service cost	$	2	$	3	$	7	$	10
Interest cost	15		11		45		33
Expected return on assets	(21)		(22)		(64)		(65)
Amortization of prior service cost	—		—		—		—
Amortization of net actuarial loss	—		3		—		9
Net periodic benefit	$	(4)	$	(5)	$	(12)	$	(13)