Restructuring - Charges Related to Restructuring Program Activities by Type of Cost (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Materials and production	$ 16,768us-gaap_CostOfGoodsSold	$ 16,954us-gaap_CostOfGoodsSold	$ 16,446us-gaap_CostOfGoodsSold
Marketing and administrative	11,606	11,911	12,776
Research and development	7,180us-gaap_ResearchAndDevelopmentExpense	7,503us-gaap_ResearchAndDevelopmentExpense	8,168us-gaap_ResearchAndDevelopmentExpense
Restructuring costs	1,013us-gaap_RestructuringCharges	1,709us-gaap_RestructuringCharges	664us-gaap_RestructuringCharges
Expenses	1,978	2,401	999
2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	227	193
Marketing and administrative	145	75
Research and development	282	75
Restructuring costs	594	898
Expenses	1,248	1,241
Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	255	249	162
Marketing and administrative	55	66	81
Research and development	1	26	57
Restructuring costs	419	765	651
Expenses	730	1,106	951
2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		4	26
Marketing and administrative		4	9
Restructuring costs		46	13
Expenses		54	48
Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	674	1,381	489
Separation Costs [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	0	0
Marketing and administrative	0	0
Research and development	0	0
Restructuring costs	566	866
Expenses	566	866
Separation Costs [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	0	0	0
Marketing and administrative	0	0	0
Research and development	0	0	0
Restructuring costs	108	481	497
Expenses	108	481	497
Separation Costs [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		0	0
Marketing and administrative		0	0
Restructuring costs		34	(8)
Expenses		34	(8)
Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	900	577	235
Accelerated Depreciation [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	204	186
Marketing and administrative	142	72
Research and development	273	76
Restructuring costs	0	0
Expenses	619	334
Accelerated Depreciation [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	225	151	92
Marketing and administrative	56	63	75
Research and development	0	27	53
Restructuring costs	0	0	0
Expenses	281	241	220
Accelerated Depreciation [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		(2)	7
Marketing and administrative		4	8
Restructuring costs		0	0
Expenses		2	15
Other [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	404	443	275
Other [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	23	7
Marketing and administrative	3	3
Research and development	9	(1)
Restructuring costs	28	32
Expenses	63	41
Other [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	30	98	70
Marketing and administrative	(1)	3	6
Research and development	1	(1)	4
Restructuring costs	311	284	154
Expenses	341	384	234
Other [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		6	19
Marketing and administrative		0	1
Restructuring costs		12	21
Expenses		$ 18	$ 41

Total costs related to goods produced and sold during the reporting period.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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