Retirement Benefits (Unaudited)

9 Months Ended

Sep. 30, 2021

Retirement Benefits [Abstract]

RETIREMENT BENEFITS

RETIREMENT BENEFITS

The cost to the company of its pension and other postretirement benefit (OPB) plans is shown in the following table:

	Three Months Ended September 30								Nine Months Ended September 30
	Pension Benefits				OPB				Pension Benefits				OPB
$ in millions	2021		2020		2021		2020		2021		2020		2021		2020
Components of net periodic benefit cost (benefit)
Service cost	$	104	$	102	$	4	$	4	$	311	$	306	$	12	$	13
Interest cost	263		307		13		17		790		920		40		50
Expected return on plan assets	(627)		(594)		(26)		(26)		(1,884)		(1,782)		(79)		(77)
Amortization of prior service (credit) cost	(3)		(15)		—		1		(7)		(45)		(1)		3
Net periodic benefit cost (benefit)	$	(263)	$	(200)	$	(9)	$	(4)	$	(790)	$	(601)	$	(28)	$	(11)

Employer Contributions

The company sponsors defined benefit pension and OPB plans, as well as defined contribution plans. We fund our defined benefit pension plans annually in a manner consistent with the Employee Retirement Income Security Act of 1974, as amended by the Pension Protection Act of 2006.

Contributions made by the company to its retirement plans are as follows:

	Three Months Ended September 30				Nine Months Ended September 30
$ in millions	2021		2020		2021		2020
Defined benefit pension plans	$	26	$	24	$	79	$	70
OPB plans	8		7		29		30
Defined contribution plans	99		116		476		472