Employee Benefits (Tables)

9 Months Ended

Sep. 30, 2013

Compensation and Retirement Disclosure [Abstract]

Schedule of components of net periodic pension benefit (income) expense and post-retirement benefit expense

	Pension Plans
	Three Months Ended September 30,					Nine Months Ended September 30,
	2013			2012		2013		2012
	(Dollars in millions)
Service cost	$	22		23		70		68
Interest cost	137			156		407		468
Expected return on plan assets	(224		)	(212	)	(672	)	(636	)
Recognition of prior service cost	1			1		4		3
Recognition of actuarial loss	20			7		61		22
Net periodic pension benefit expense (income)	$	(44	)	(25	)	(130	)	(75	)

Net periodic post-retirement benefit expense (income) included the following components:

	Post-Retirement Benefit Plans
	Three Months Ended September 30,					Nine Months Ended September 30,
	2013			2012		2013		2012
	(Dollars in millions)
Service cost	$	6		5		18		16
Interest cost	35			44		105		131
Expected return on plan assets	(10		)	(11	)	(30	)	(33	)
Recognition of actuarial loss	1			—		3		—
Net periodic post-retirement benefit expense (income)	$	32		38		96		114

Net periodic pension benefit expense (income) included the following components:

	Pension Plans
	Three Months Ended September 30,					Nine Months Ended September 30,
	2013			2012		2013		2012
	(Dollars in millions)
Service cost	$	22		23		70		68
Interest cost	137			156		407		468
Expected return on plan assets	(224		)	(212	)	(672	)	(636	)
Recognition of prior service cost	1			1		4		3
Recognition of actuarial loss	20			7		61		22
Net periodic pension benefit expense (income)	$	(44	)	(25	)	(130	)	(75	)