Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2014

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

Components of Net Periodic Benefit Cost

The components of net periodic benefit cost 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)	2014			2013			2014			2013
Service cost	$	8		$	10		$	15		$	19
Interest cost	22			20			44			39
Expected return on plan assets	(33		)	(33		)	(66		)	(66		)
Amortization of prior service cost	2			1			3			2
Amortization of net loss	7			19			15			38
Net periodic defined benefit cost	$	6		$	17		$	11		$	32

Non-Qualified Defined Benefit Pension Plan	Three Months Ended June 30,						Six Months Ended June 30,
(in millions)	2014			2013			2014			2013
Service cost	$	1		$	1		$	2		$	2
Interest cost	3			2			5			5
Amortization of prior service cost (credit)	(1		)	(1		)	(2		)	(1		)
Amortization of net loss	1			3			3			5
Net periodic defined benefit cost	$	4		$	5		$	8		$	11

Postretirement Benefit Plan	Three Months Ended June 30,						Six Months Ended June 30,
(in millions)	2014			2013			2014			2013
Interest cost	$	1		$	1		$	2		$	2
Expected return on plan assets	(1		)	(1		)	(2		)	(2		)
Amortization of net loss	—			1			—			1
Net periodic postretirement benefit cost	$	—		$	1		$	—		$	1