Goodwill and Intangible Assets (Details 2) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets
Gross amount of amortizable intangible assets	$ 10,800	$ 11,000
Accumulated amortization of intangible assets	5,300	4,900
Indefinite-lived intangible assets related to in-process research and development acquired in a business combination	377	$ 134
Estimated annual amortization expense, intangible assets, 2015	680
Estimated annual amortization expense, intangible assets, 2016	660
Estimated annual amortization expense, intangible assets, 2017	650
Estimated annual amortization expense, intangible assets, 2018	570
Estimated annual amortization expense, intangible assets, 2019	$ 530
Minimum
Goodwill and Intangible Assets
Average amortization period, intangible assets	2 years
Maximum
Goodwill and Intangible Assets
Average amortization period, intangible assets	20 years
Average
Goodwill and Intangible Assets
Average amortization period, intangible assets	12 years