Pension and Postretirement Benefit Plans (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Maximum
Net periodic benefit cost (benefit)
Defined benefit plan estimated future employer contributions	$ 1,000
Minimum
Net periodic benefit cost (benefit)
Defined benefit plan estimated future employer contributions	800
Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Contributions made to the Company's plans	517	556
United States Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	206	201	183
Interest cost	626	638	619
Expected return on plan assets	(927)	(929)	(906)
Amortization of prior service cost (benefit)	11	13	16
Amortization of net actuarial (gain) loss	334	221	99
Net periodic benefit cost (benefit)	250	144	11
Settlements, curtailments, special termination benefits and other	1		26
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	251	144	37
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year
Amortization of prior service cost (benefit)	6
Amortization of net actuarial (gain) loss	470
Total amortization expected over the next fiscal year	476
Weighted-average assumptions used to determine net cost for years ended
Discount rate	5.23%	5.77%	6.14%
Expected return on assets	8.50%	8.50%	8.50%
Percentage decrease in expected return on assets in next fiscal year from the prior year	0.25%
Compensation rate increase	4.00%	4.30%	4.30%
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.15%	5.23%	5.77%
Compensation rate increase	4.00%	4.00%	4.30%
Percentage decrease in discount rate obligation from the prior year	1.08%
Additional expected pension expense in next fiscal year from the prior year	30
Company's assumption for the expected return on plan assets
Expected rate of return on plan assets in next fiscal year	8.25%
Amount of company's common stock contributed by company			600
Other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss
Prior service cost (benefit)	8
Amortization of prior service cost (benefit)	(11)	(13)	(16)
Net actuarial (gain) loss	1,976	227	585
Amortization of net actuarial (gain) loss	(334)	(221)	(99)
Total recognized in other comprehensive (income) loss	1,639	(7)	470
Total recognized in net periodic benefit cost (benefit) and other comprehensive (income) loss	1,890	137	507
United States Qualified Pension Benefits
Asset Allocation assumption next fiscal year
Global equities assumption next fiscal year	37.00%
Private equities assumption next fiscal year	16.00%
Fixed-income securities assumption next fiscal year	26.00%
Absolute return investments assumption next fiscal year	16.00%
Commodities assumption next fiscal year	5.00%
Company's assumption for the expected return on plan assets
Global equities assumption next fiscal year	7.75%
Private equities assumption next fiscal year	11.75%
Fixed-income securities assumption next fiscal year	4.23%
Absolute return investments assumption next fiscal year	6.00%
Commodities assumption next fiscal year	6.00%
Other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss
Rate of return on plan assets	8.70%	14.40%	12.60%
Average annual actual return on plan assets over the past 10 years	8.10%
Average annual actual return on plan assets over the past 25 years	10.40%
International Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	124	105	98
Interest cost	261	241	235
Expected return on plan assets	(289)	(278)	(260)
Amortization of transition (asset) obligation	(2)	1	3
Amortization of prior service cost (benefit)	(14)	(4)	(4)
Amortization of net actuarial (gain) loss	116	84	42
Net periodic benefit cost (benefit)	196	149	114
Settlements, curtailments, special termination benefits and other	2	(22)	25
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	198	127	139
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year
Amortization of transition (asset) obligation	(2)
Amortization of prior service cost (benefit)	(17)
Amortization of net actuarial (gain) loss	120
Total amortization expected over the next fiscal year	101
Weighted-average assumptions used to determine net cost for years ended
Discount rate	5.04%	5.30%	5.53%
Expected return on assets	6.58%	6.90%	6.86%
Compensation rate increase	3.59%	3.72%	3.50%
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.58%	5.04%	5.30%
Compensation rate increase	3.52%	3.59%	3.72%
Other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss
Transition (asset) obligation	(2)	(1)	(2)
Amortization of transition (asset) obligation	2	(1)	(3)
Prior service cost (benefit)	(32)	(91)	19
Amortization of prior service cost (benefit)	14	4	4
Net actuarial (gain) loss	315	104	224
Amortization of net actuarial (gain) loss	(116)	(84)	(42)
Foreign currency	(17)	(19)	(101)
Total recognized in other comprehensive (income) loss	164	(88)	99
Total recognized in net periodic benefit cost (benefit) and other comprehensive (income) loss	362	39	238
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	61	55	51
Interest cost	92	88	97
Expected return on plan assets	(77)	(83)	(86)
Amortization of prior service cost (benefit)	(72)	(94)	(81)
Amortization of net actuarial (gain) loss	102	85	66
Net periodic benefit cost (benefit)	106	51	47
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	106	51	47
Contributions made to the Company's plans	65	62
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year
Amortization of prior service cost (benefit)	(72)
Amortization of net actuarial (gain) loss	109
Total amortization expected over the next fiscal year	37
Weighted-average assumptions used to determine net cost for years ended
Discount rate	5.09%	5.62%	6.14%
Expected return on assets	7.38%	7.30%	7.24%
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.04%	5.09%	5.62%
Percentage decrease in discount rate obligation from the prior year	1.05%
Other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss
Prior service cost (benefit)		69	(169)
Amortization of prior service cost (benefit)	72	94	81
Net actuarial (gain) loss	212	89	36
Amortization of net actuarial (gain) loss	(102)	(85)	(66)
Foreign currency	(2)	(1)	(1)
Total recognized in other comprehensive (income) loss	180	166	(119)
Total recognized in net periodic benefit cost (benefit) and other comprehensive (income) loss	$ 286	$ 217	$ (72)