Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2014

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   September 30,						Nine months ended    September 30,
	2014			2013			2014			2013
	(Millions)
Components of net periodic benefit cost:
Service cost	$	10		$	11		$	30		$	33
Interest cost	15			12			46			38
Expected return on plan assets	(19		)	(15		)	(57		)	(45		)
Amortization of prior service cost	—			1			—			1
Amortization of net actuarial loss	10			15			29			45
Net periodic benefit cost	$	16		$	24		$	48		$	72

	Other Postretirement Benefits
	Three months ended   September 30,						Nine months ended    September 30,
	2014			2013			2014			2013
	(Millions)
Components of net periodic benefit cost (credit):
Service cost	$	—		$	1		$	1		$	2
Interest cost	2			2			7			8
Expected return on plan assets	(3		)	(3		)	(9		)	(7		)
Amortization of prior service credit	(5		)	(3		)	(15		)	(7		)
Amortization of net actuarial loss	—			1			—			4
Reclassification to regulatory liability	1			1			3			1
Net periodic benefit cost (credit)	$	(5	)	$	(1	)	$	(13	)	$	1

Schedule of Regulatory Assets / Liabilities [Table Text Block]

Amounts recognized in regulatory assets/liabilities include:

	Three months ended   September 30,						Nine months ended    September 30,
	2014			2013			2014			2013
	(Millions)
Amortization of prior service credit	$	(3	)	$	(1	)	$	(9	)	$	(4	)
Amortization of net actuarial loss	—			—			—			2