Restructuring - Charges Related to Restructuring Program Activities by Type of Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Expenses	$ 1,110	$ 1,978	$ 2,401
Separation Costs
Restructuring Cost and Reserve [Line Items]
Expenses	208	674	1,381
Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Expenses	174	900	577
Other
Restructuring Cost and Reserve [Line Items]
Expenses	728	404	443
2013 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Expenses	527	1,248	1,241
2013 Restructuring Program | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	43	227	193
2013 Restructuring Program | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	70	145	75
2013 Restructuring Program | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	51	282	75
2013 Restructuring Program | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	363	594	898
2013 Restructuring Program | Separation Costs
Restructuring Cost and Reserve [Line Items]
Expenses	199	566	866
2013 Restructuring Program | Separation Costs | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
2013 Restructuring Program | Separation Costs | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
2013 Restructuring Program | Separation Costs | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
2013 Restructuring Program | Separation Costs | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	199	566	866
2013 Restructuring Program | Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Expenses	129	619	334
2013 Restructuring Program | Accelerated Depreciation | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	41	204	186
2013 Restructuring Program | Accelerated Depreciation | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	52	142	72
2013 Restructuring Program | Accelerated Depreciation | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	36	273	76
2013 Restructuring Program | Accelerated Depreciation | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
2013 Restructuring Program | Other
Restructuring Cost and Reserve [Line Items]
Expenses	199	63	41
2013 Restructuring Program | Other | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	2	23	7
2013 Restructuring Program | Other | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	18	3	3
2013 Restructuring Program | Other | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	15	9	(1)
2013 Restructuring Program | Other | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	164	28	32
Merger Restructuring Program
Restructuring Cost and Reserve [Line Items]
Expenses	583	730	1,106
Merger Restructuring Program | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	318	255	249
Merger Restructuring Program | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	8	55	66
Merger Restructuring Program | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	1	1	26
Merger Restructuring Program | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	256	419	765
Merger Restructuring Program | Separation Costs
Restructuring Cost and Reserve [Line Items]
Expenses	9	108	481
Merger Restructuring Program | Separation Costs | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
Merger Restructuring Program | Separation Costs | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
Merger Restructuring Program | Separation Costs | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
Merger Restructuring Program | Separation Costs | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	9	108	481
Merger Restructuring Program | Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Expenses	45	281	241
Merger Restructuring Program | Accelerated Depreciation | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	37	225	151
Merger Restructuring Program | Accelerated Depreciation | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	7	56	63
Merger Restructuring Program | Accelerated Depreciation | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	1	0	27
Merger Restructuring Program | Accelerated Depreciation | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	0	0	0
Merger Restructuring Program | Other
Restructuring Cost and Reserve [Line Items]
Expenses	529	341	384
Merger Restructuring Program | Other | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses	281	30	98
Merger Restructuring Program | Other | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses	1	(1)	3
Merger Restructuring Program | Other | Research and development
Restructuring Cost and Reserve [Line Items]
Expenses	0	1	(1)
Merger Restructuring Program | Other | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses	$ 247	$ 311	284
2008 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Expenses			54
2008 Restructuring Program | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses			4
2008 Restructuring Program | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses			4
2008 Restructuring Program | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses			46
2008 Restructuring Program | Separation Costs
Restructuring Cost and Reserve [Line Items]
Expenses			34
2008 Restructuring Program | Separation Costs | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses			0
2008 Restructuring Program | Separation Costs | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses			0
2008 Restructuring Program | Separation Costs | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses			34
2008 Restructuring Program | Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Expenses			2
2008 Restructuring Program | Accelerated Depreciation | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses			(2)
2008 Restructuring Program | Accelerated Depreciation | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses			4
2008 Restructuring Program | Accelerated Depreciation | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses			0
2008 Restructuring Program | Other
Restructuring Cost and Reserve [Line Items]
Expenses			18
2008 Restructuring Program | Other | Materials and production
Restructuring Cost and Reserve [Line Items]
Expenses			6
2008 Restructuring Program | Other | Marketing and administrative
Restructuring Cost and Reserve [Line Items]
Expenses			0
2008 Restructuring Program | Other | Restructuring costs
Restructuring Cost and Reserve [Line Items]
Expenses			$ 12