Business Combinations and Divestitures (Details) ¥ / shares in Units, $ / shares in Units, ¥ in Billions		1 Months Ended		3 Months Ended	4 Months Ended	9 Months Ended
	Jun. 16, 2017 USD ($) $ / shares	Oct. 30, 2018 USD ($)	Oct. 30, 2018 JPY (¥) ¥ / shares	Apr. 02, 2017 USD ($)	Oct. 01, 2017 USD ($)	Sep. 30, 2018 USD ($)	Oct. 01, 2017 USD ($)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Goodwill						$ 30,702,000,000		$ 31,906,000,000
Payments to acquire businesses						897,000,000	$ 34,646,000,000
Medical Devices
Business Acquisition [Line Items]
Goodwill						12,850,000,000		$ 13,922,000,000
Actelion
Business Acquisition [Line Items]
Share price | $ / shares	$ 280
Goodwill, Subsequent Recognition of Deferred Tax Asset					$ 200,000,000
Business Combination, Initial Accounting Incomplete, Adjustment, Current Liabilities					$ 400,000,000
Goodwill						6,161,000,000
Payments to acquire businesses	$ 29,600,000,000
Weighted average useful life	9 years
Acquisition related costs						200,000,000
Actelion | Minimum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	4 years
Actelion | Maximum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years
Idorsia
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	9.90%
Convertible Note, Equity Interest, Percentage	22.10%
Idorsia | Convertible Debt
Business Acquisition [Line Items]
Long-term Debt	$ 500,000,000
Debt Instrument, Term	10 years
Idorsia | Line of Credit
Business Acquisition [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 250,000,000
Idorsia | Debt Instrument, Redemption, Period One | Convertible Debt
Business Acquisition [Line Items]
Convertible Note, Equity Interest, Percentage	16.00%
Debt Instrument, Restrictive Covenants, Shareholder Ownership Threshold, Percent	20.00%
AMO
Business Acquisition [Line Items]
Weighted average useful life				14 years 4 months 24 days
AMO | Medical Devices
Business Acquisition [Line Items]
Goodwill				$ 1,700,000,000
Payments to acquire businesses				4,300,000,000
Total amortizable intangibles				$ 2,300,000,000
Discontinued Operations, Held-for-sale or Disposed of by Sale | LifeScan
Business Acquisition [Line Items]
Disposal group consideration						2,100,000,000
Disposal group inventory						100,000,000
Disposal group property, plant and equipment						100,000,000
Disposal group intangible assets						100,000,000
Disposal group goodwill						1,000,000,000
Liabilities retained						400,000,000
Discontinued Operations, Held-for-sale or Disposed of by Sale | AdvancedSterilizationProducts
Business Acquisition [Line Items]
Disposal group consideration						2,700,000,000
Disposal group inventory						200,000,000
Disposal group property, plant and equipment						100,000,000
Disposal group goodwill						200,000,000
Receivables retained						100,000,000
Assets held for sale, current						200,000,000
Discontinued Operations, Held-for-sale or Disposed of by Sale | Supply Chain
Business Acquisition [Line Items]
Disposal group property, plant and equipment						100,000,000
Assets held for sale, current						$ 300,000,000
Measurement Input, Discount Rate [Member] | Actelion | In-process research and development
Business Acquisition [Line Items]
Fair Value Inputs, Discount Rate						0.09
Subsequent Event | Ci:z Holdings Co. Ltd. [Member]
Business Acquisition [Line Items]
Share price | ¥ / shares			¥ 5,900
Business acquisition cost		$ 2,000,000,000	¥ 230
Foreign exchange rate			112.82