Financial Instruments, Summary of derivative and non-derivative financial instruments outstanding measured at fair value on a recurring basis (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	$ 6,647	$ 5,771
Notional amount, derivative and non-derivative financial instruments liabilities	1,766	744
Fair value, derivative and non-derivative financial instruments assets	1,955	1,649
Fair value, derivative and non-derivative financial instruments liabilities	61	50
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as net investment hedges: [Member] | Basis swaps [Member] | Accrued liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	500	0
Fair value, derivative and non-derivative financial instruments liabilities	5	0
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as net investment hedges: [Member] | Basis swaps [Member] | Other liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	444	0
Fair value, derivative and non-derivative financial instruments liabilities	5	0
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as cash flow hedges [Member] | Cross-currency swaps [Member] | Other assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	2,300	2,000
Fair value, derivative and non-derivative financial instruments assets	258	30
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as cash flow hedges [Member] | Cross-currency swaps [Member] | Prepaid expenses and other current assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	0	0
Fair value, derivative and non-derivative financial instruments assets	18	5
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as cash flow hedges [Member] | Interest rate swaps [Member] | Other assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	600	0
Fair value, derivative and non-derivative financial instruments assets	5	0
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as cash flow hedges [Member] | Interest rate swaps [Member] | Other liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	400	0
Fair value, derivative and non-derivative financial instruments liabilities	8	0
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as fair value hedges: [Member] | Interest rate swaps [Member] | Other assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	2,000	2,000
Fair value, derivative and non-derivative financial instruments assets	44	10
Derivatives: [Member] | Derivatives designated as hedges: [Member] | Derivatives designated as fair value hedges: [Member] | Interest rate swaps [Member] | Prepaid expenses and other current assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	0	0
Fair value, derivative and non-derivative financial instruments assets	13	6
Derivatives: [Member] | Derivatives not designated as hedges: [Member] | Commodities [Member] | Prepaid expenses and other current assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	11	0
Fair value, derivative and non-derivative financial instruments assets	4	2
Derivatives: [Member] | Derivatives not designated as hedges: [Member] | Commodities [Member] | Accrued liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	15	28
Fair value, derivative and non-derivative financial instruments liabilities	1	1
Derivatives: [Member] | Derivatives not designated as hedges: [Member] | Embedded derivatives [Member] | Prepaid expenses and other current assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	76	77
Fair value, derivative and non-derivative financial instruments assets	11	3
Derivatives: [Member] | Derivatives not designated as hedges: [Member] | Foreign currency [Member] | Prepaid expenses and other current assets [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	48	107
Fair value, derivative and non-derivative financial instruments assets	0	0
Derivatives: [Member] | Derivatives not designated as hedges: [Member] | Foreign currency [Member] | Accrued liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	372	680
Fair value, derivative and non-derivative financial instruments liabilities	7	13
Non-derivatives: [Member] | Available-for-sale securities [Member] | Short-term investments [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments assets	1,612	1,587
Fair value, derivative and non-derivative financial instruments assets	1,602	1,593
Non-derivatives: [Member] | Performance share awards [Member] | Accrued liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	21	22
Fair value, derivative and non-derivative financial instruments liabilities	21	22
Non-derivatives: [Member] | Performance share awards [Member] | Other liabilities [Member]
Derivative and non-derivative assets and liabilities at fair value, net, by balance sheet classification [Abstract]
Notional amount, derivative and non-derivative financial instruments liabilities	14	14
Fair value, derivative and non-derivative financial instruments liabilities	$ 14	$ 14