Pension Plans, Retirement Benefits and Savings Plans (details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pension Plans [Member]
Defined benefit plan disclosure
Service cost	$ 24	$ 24	$ 49	$ 48
Interest cost on benefit obligation	34	32	68	64
Expected return on plan assets	(45)	(46)	(91)	(92)
Net periodic benefit cost, amortization of unrecognized prior service benefit		(1)		(2)
Amortization of unrecognized net actuarial loss	19	15	38	30
Net periodic benefit cost, net benefit expense	32	24	64	48
Postretirement Benefit Plans [Member]
Defined benefit plan disclosure
Interest cost on benefit obligation	4	3	7	7
Expected return on plan assets	(1)		(1)
Net periodic benefit cost, net benefit expense	$ 3	$ 3	$ 6	$ 7