Loans Payable, Long-Term Debt and Other Commitments - Narrative (Details)	1 Months Ended			12 Months Ended
	Feb. 28, 2015 USD ($)	Oct. 31, 2014 USD ($)	Aug. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Nov. 30, 2014 USD ($)	Oct. 31, 2014 EUR (€)
Debt Instrument [Line Items]
Long-term debt, current maturities				$ 2,300,000,000	$ 1,000,000,000
Loans payable and current portion of long-term debt				2,585,000,000	2,704,000,000
Long-Term Debt				23,929,000,000	18,699,000,000
Par Value of Debt	$ 8,000,000,000.0							€ 2,500,000,000.0
Proceeds from Debt, Net of Issuance Costs	7,900,000,000
Repayments of Long-term Debt				2,906,000,000	6,617,000,000	$ 1,775,000,000
Proceeds from Issuance of Debt		$ 3,100,000,000
Repayments of Debt		2,500,000,000
Extinguishment of Debt, Amount		$ 1,800,000,000
Debt Instrument, Repurchased Face Amount							$ 2,000,000,000.0
Loss on extinguishment of debt				$ 0	628,000,000	0
Maximum total debt to capitalization ratio allowable by financial covenants under certain borrowings (not to exceed)				60.00%
Long-term debt, maturities, repayments of principal in 2016				$ 2,400,000,000
Long-term debt, maturities, repayments of principal in 2017				317,000,000
Long-term debt, maturities, repayments of principal in 2018				3,000,000,000
Long-term debt, maturities, repayments of principal in 2019				1,300,000,000
Long-term debt, maturities, repayments of principal in 2020				2,000,000,000
Available borrowing capacity under credit facility			$ 6,000,000,000.0
Line of Credit Facility, Term			5 years
Rental expense under operating leases net of sublease income				303,000,000	350,000,000	$ 367,000,000
Minimum aggregate rental commitments under noncancellable leases in 2016				213,000,000
Minimum aggregate rental commitments under noncancellable leases in 2017				136,000,000
Minimum aggregate rental commitments under noncancellable leases in 2018				114,000,000
Minimum aggregate rental commitments under noncancellable leases in 2019				97,000,000
Minimum aggregate rental commitments under noncancellable leases in 2020				69,000,000
Minimum aggregate rental commitments under noncancellable leases thereafter				160,000,000
Cubist Pharmaceuticals Inc
Debt Instrument [Line Items]
Repayments of Long-term Debt	1,900,000,000
Other Variable Rate Debt
Debt Instrument [Line Items]
Long-Term Debt				$ 225,000,000	$ 309,000,000
Average variable rate of other long term debt borrowings				0.00%	0.00%
Other Foreign Debt
Debt Instrument [Line Items]
Long-Term Debt				$ 43,000,000	$ 53,000,000
Maximum rate of foreign borrowings (up to)				4.75%	6.25%
6.30% debentures due 2026
Debt Instrument [Line Items]
Long-Term Debt				$ 152,000,000	$ 152,000,000
Stated interest rate of senior unsecured notes				6.30%
Floating-rate notes due 2017
Debt Instrument [Line Items]
Long-Term Debt				$ 300,000,000	0
Par Value of Debt	300,000,000
Floating-rate notes due 2020
Debt Instrument [Line Items]
Long-Term Debt				700,000,000	0
Par Value of Debt	$ 700,000,000
1.85% notes due 2020
Debt Instrument [Line Items]
Long-Term Debt				$ 1,243,000,000	0
Stated interest rate of senior unsecured notes	1.85%			1.85%
Par Value of Debt	$ 1,250,000,000.00
2.35% notes due 2022
Debt Instrument [Line Items]
Long-Term Debt				$ 1,237,000,000	0
Stated interest rate of senior unsecured notes	2.35%			2.35%
Par Value of Debt	$ 1,250,000,000.00
2.75% notes due 2025
Debt Instrument [Line Items]
Long-Term Debt				$ 2,496,000,000	0
Stated interest rate of senior unsecured notes	2.75%			2.75%
Par Value of Debt	$ 2,500,000,000.0
3.70% notes due 2045
Debt Instrument [Line Items]
Long-Term Debt				$ 1,989,000,000	0
Stated interest rate of senior unsecured notes	3.70%			3.70%
Par Value of Debt	$ 2,000,000,000.0
Commercial paper
Debt Instrument [Line Items]
Loans payable and current portion of long-term debt					$ 1,500,000,000
Weighted-average interest rate of commercial paper				0.07%	0.15%
Short Term Foreign Borrowings
Debt Instrument [Line Items]
Loans payable and current portion of long-term debt				$ 10,000,000	$ 55,000,000
Notes Subject To Repayment At Option Of Holder
Debt Instrument [Line Items]
Loans payable and current portion of long-term debt				$ 226,000,000	$ 143,000,000