Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Costs

Net periodic benefit cost (income) consisted of the following:

	For the Six Months Ended June 30,												For the Three Months Ended June 30,
	Pension						Postretirement						Pension						Postretirement
	2016			2015			2016			2015			2016			2015			2016			2015
	(in millions)
Service cost	$	37		$	43		$	8		$	9		$	19		$	22		$	4		$	5
Interest cost	141			168			40			51			70			84			19			25
Expected return on plan assets	(277		)	(270		)	—			—			(139		)	(135		)	—			—
Amortization:
Net loss	87			117			16			23			43			58			9			11
Prior service cost (credit)	2			4			(19		)	(20		)	1			2			(9		)	(10		)
Termination and curtailment	20			—			—			—			—			—			—			—
Net periodic benefit cost (income)	$	10		$	62		$	45		$	63		$	(6	)	$	31		$	23		$	31