Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2019

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost (credit) is as follows:

	Pension Benefits
	Three Months Ended   September 30,						Nine Months Ended   September 30,
	2019			2018			2019			2018
	(Millions)
Components of net periodic benefit cost (credit):
Service cost	$	11		$	12		$	33		$	37
Interest cost	13			12			38			35
Expected return on plan assets	(15		)	(16		)	(46		)	(47		)
Amortization of net actuarial loss	3			6			11			17
Net actuarial loss from settlements	1			1			1			2
Net periodic benefit cost (credit)	$	13		$	15		$	37		$	44

	Other Postretirement Benefits
	Three Months Ended   September 30,						Nine Months Ended   September 30,
	2019			2018			2019			2018
	(Millions)
Components of net periodic benefit cost (credit):
Service cost	$	1		$	1		$	1		$	1
Interest cost	2			1			6			5
Expected return on plan assets	(3		)	(2		)	(8		)	(8		)
Amortization of prior service credit	—			—			—			(1		)
Reclassification to regulatory liability	—			—			1			1
Net periodic benefit cost (credit)	$	—		$	—		$	—		$	(2	)