Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2021

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Components of Net Periodic Benefit Cost

The components of net periodic benefit cost (credit) for the Corporation's qualified pension plan, non-qualified pension plan and postretirement benefit plan are as follows.

Qualified Defined Benefit Pension Plan	Three Months Ended June 30,				Six Months Ended June 30,
(in millions)	2021		2020 (a)		2021		2020 (a)
Service cost	$	9	$	8	$	19	$	16
Other components of net benefit credit:
Interest cost	15		17		30		35
Expected return on plan assets	(51)		(45)		(101)		(91)
Amortization of prior service credit	(4)		(5)		(9)		(10)
Amortization of net loss	8		10		15		19
Total other components of net benefit credit	(32)		(23)		(65)		(47)
Net periodic defined benefit credit	$	(23)	$	(15)	$	(46)	$	(31)

(a)Recast to reflect the retrospective application of the Corporation's election to change the accounting method for certain components of defined pension benefit credit, effective January 1, 2021. For the three months ended June 30, 2020, expected return on plan assets increased $3 million and amortization of net loss was reduced by $3 million, resulting in an increase of $6 million to total other components of net benefit credit. For the six months ended June 30, 2020, expected return on plan assets increased $6 million and amortization of net loss was reduced by $8 million, resulting in an increase of $14 million to total other components of net benefit credit. Refer to Note 1 for further information.

Non-Qualified Defined Benefit Pension Plan	Three Months Ended June 30,				Six Months Ended June 30,
(in millions)	2021		2020		2021		2020
Service cost	$	1	$	—	$	1	$	1
Other components of net benefit cost:
Interest cost	1		2		3		4
Amortization of prior service credit	(2)		(2)		(3)		(4)
Amortization of net loss	2		2		5		4
Total other components of net benefit cost	1		2		5		4
Net periodic defined benefit cost	$	2	$	2	$	6	$	5

Postretirement Benefit Plan	Three Months Ended June 30,				Six Months Ended June 30,
(in millions)	2021		2020		2021		2020
Other components of net benefit credit:
Expected return on plan assets	$	—	$	(1)	(1)		(1)
Net periodic defined benefit credit	$	—	$	(1)	$	(1)	$	(1)