Goodwill and Intangible Assets (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets
Gross amount of amortizable intangible assets	10,900,000,000	$ 10,900,000,000
Accumulated amortization of intangible assets	5,000,000,000	4,900,000,000
Indefinite-lived intangible assets related to in-process research and development acquired in a business combination	134,000,000	134,000,000
Estimated annual amortization expense, intangible assets, 2015	680,000,000
Estimated annual amortization expense, intangible assets, 2016	660,000,000
Estimated annual amortization expense, intangible assets, 2017	650,000,000
Estimated annual amortization expense, intangible assets, 2018	570,000,000
Estimated annual amortization expense, intangible assets, 2019	530,000,000
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