Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost (credit) is as follows:

	Pension Benefits
	Three months ended    March 31,
	2015			2014
	(Millions)
Components of net periodic benefit cost:
Service cost	$	14		$	10
Interest cost	15			16
Expected return on plan assets	(19		)	(19		)
Amortization of net actuarial loss	11			9
Net periodic benefit cost	$	21		$	16

	Other Postretirement Benefits
	Three months ended    March 31,
	2015			2014
	(Millions)
Components of net periodic benefit cost (credit):
Service cost	$	1		$	1
Interest cost	2			2
Expected return on plan assets	(3		)	(3		)
Amortization of prior service credit	(4		)	(5		)
Reclassification to regulatory liability	1			1
Net periodic benefit cost (credit)	$	(3	)	$	(4	)