Employee Benefit Plans (Net Periodic Benefit Cost) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011		Sep. 30, 2010
Pension Benefits [Member]
Service cost	$ 27	$ 25	$ 81		$ 77
Interest cost	65	66	194		200
Expected return on plan assets	(110)	(103)	(331)		(308)
Amortization of prior service cost (credit)	0	1	2		3
Amortization of net loss	24	15	72		45
Settlements and curtailments			0	[1]	84	[1]
Special termination benefits			0	[2]	10	[2]
Net periodic benefit cost	6	4	18		111
Other Postretirement Benefits [Member]
Service cost	12	13	36		41
Interest cost	24	26	71		76
Expected return on plan assets	(21)	(17)	(60)		(52)
Amortization of prior service cost (credit)	(3)	(2)	(10)		(5)
Amortization of net loss	3	3	9		9
Settlements and curtailments			(1)	[1]	37	[1]
Special termination benefits			0	[2]	1	[2]
Net periodic benefit cost	$ 15	$ 23	$ 45		$ 107

[1] 2010 amounts relate to the sale of Peoples and a workforce reduction program.

[2] Represents a one-time special termination benefit for certain employees in connection with a workforce reduction program.