Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost (credit) is as follows:

	Pension Benefits
	Three Months Ended  March 31,
	2020			2019
	(Millions)
Components of net periodic benefit cost (credit):
Service cost	$	8		$	11
Interest cost	10			12
Expected return on plan assets	(13		)	(15		)
Amortization of net actuarial loss	4			4
Net actuarial loss from settlements	6			—
Net periodic benefit cost (credit)	$	15		$	12

	Other Postretirement Benefits
	Three Months Ended  March 31,
	2020			2019
	(Millions)
Components of net periodic benefit cost (credit):
Interest cost	$	2		$	2
Expected return on plan assets	(3		)	(2		)
Reclassification to regulatory liability	1			—
Net periodic benefit cost (credit)	$	—		$	—