Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Costs

Net periodic benefit cost consisted of the following:

		For the Three Months Ended March 31,
		Pension						Postretirement
		2016			2015			2016			2015
	(in millions)
Service cost		$	18		$	21		$	4		$	4
Interest cost		71			84			21			26
Expected return on plan assets		(138		)	(135		)	—			—
Amortization:
Net loss		44			59			7			12
Prior service cost (credit)		1			2			(10		)	(10		)
Termination and curtailment		20			—			—			—
Net periodic benefit cost		$	16		$	31		$	22		$	32