Postretirement Plans (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,406	$ 1,176	$ 1,090
Interest cost	3,116	3,002	2,964
Expected return on plan assets	(3,741)	(3,850)	(3,738)
Amortization of prior service costs	244	248	242
Recognized net actuarial loss	1,254	777	650
Settlement/curtailment/transfer loss	64	14	13
Net periodic benefit cost	2,343	1,367	1,221
Net periodic benefit cost included in Earnings from operations	1,648	1,101	879
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	221	121	132
Interest cost	484	404	466
Expected return on plan assets	(6)	(6)	(5)
Amortization of prior service costs	(96)	(78)	(90)
Recognized net actuarial loss	178	56	92
Settlement/curtailment/transfer loss	3
Net periodic benefit cost	784	497	595
Net periodic benefit cost included in Earnings from operations	$ 692	$ 480	$ 615