Pension Plans, Retirement Benefits and Savings Plans (details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Plans [Member]
Defined benefit plan disclosure
Service cost	$ 27	$ 29
Interest cost on benefit obligation	38	33
Expected return on plan assets	(54)	(52)
Amortization of unrecognized net actuarial loss	16	27
Net periodic benefit cost	27	37
Postretirement Benefit Plans [Member]
Defined benefit plan disclosure
Interest cost on benefit obligation	2	2
Net periodic benefit cost, amortization of unrecognized prior service benefit	(1)
Net periodic benefit cost	$ 1	$ 2