Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Benefit Plans (Textual)
Gain arising during the period related to plan amendments			$ 0	$ 328
Pension Plan [Member]
Components of net periodic benefit cost:
Service cost	30	35	60	71
Interest cost	23	22	46	44
Expected return on plan assets	(33)	(34)	(66)	(66)
Amortization of:
Prior service credit	(5)	(6)	(10)	(9)
Net actuarial loss	9	15	17	29
Net periodic benefit cost	24	32	47	69
Employee Benefit Plans (Textual)
Decrease to pension liabilities related to plan amendments				328
Gain arising during the period related to plan amendments				328
Contributions to pension plans			22	22
Other Postretirement Benefit Plan [Member]
Components of net periodic benefit cost:
Service cost	1	3	3	6
Interest cost	4	5	8	9
Expected return on plan assets	0	0	0	0
Amortization of:
Prior service credit	(4)	(3)	(9)	(6)
Net actuarial loss	0	0	0	0
Net periodic benefit cost	1	5	2	9
Employee Benefit Plans (Textual)
Contributions to pension plans			$ 9	$ 8