Retirement Plans (Schedule of Net Periodic Benefit Cost and Other Changes in Plan Assets and Benefit Obligations Recognized n Other Comprehensive Gain (Loss), Before the Effect of Income Taxes) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Service cost	$ (30)	$ (21)	$ (20)
Interest cost	(13)	(13)	(13)
Expected return on plan assets	10	9	10
Amortization of prior service cost and transition amount	1	1
Recognized actuarial loss	(8)	(5)	(2)
Net periodic benefit cost	(40)	(29)	(25)
Net actuarial gain (loss)	28	(87)	(10)
Recognized net actuarial loss	8	5	2
Prior service cost and transition amount	(1)		12
Total recognized in OCI	35	(82)	4
Total recognized in net periodic benefit cost and OCI	$ (5)	$ (111)	$ (21)
Discount rate	2.90%	4.20%	4.20%
Expected return on plan assets	3.70%	4.20%	4.60%
Rate of compensation increase	3.00%	3.00%	1.50%
Weighted-average discount rate used in the determination of the projected benefit obligations	3.20%	2.90%	4.20%