Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Derivative Financial Instruments and Hedging Activities - Derivatives Income (Losses) Recognized in Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivatives, Fair Value [Line Items]
Total		$ 106		$ 109
Interest expense	$ 803	635	$ 1,535	1,231
Other operating expenses	159	135	303	266
Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Loss	(57)	23	(35)	22
Gains (Losses) Reclassified From Accumulated Other Comprehensive Loss Into Income	74	(30)	53	(33)
Cash Flow Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Loss	1	(1)	5	1
Gains (Losses) Reclassified From Accumulated Other Comprehensive Loss Into Income	0	0	(3)	1
Cash Flow Hedging [Member] \| Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Loss	(58)	24	(40)	21
Gains (Losses) Reclassified From Accumulated Other Comprehensive Loss Into Income	74	(30)	56	(34)
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts		18		29
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts		1		(1)
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts		49		55
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts		(4)		(9)
Foreign currency derivatives		$ 42		$ 35
Other Operating Income (Expense) [Member]
Derivatives, Fair Value [Line Items]
Total	(201)		(155)
Other Operating Income (Expense) [Member] \| Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Hedged items	0		0
Interest rate contracts and Foreign currency contracts	0		0
Other Operating Income (Expense) [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts	0		0
Other Operating Income (Expense) [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts	(92)		(68)
Other Operating Income (Expense) [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts	0		0
Foreign currency derivatives	(109)		(87)
Interest Expense [Member]
Derivatives, Fair Value [Line Items]
Total	(31)		(39)
Interest Expense [Member] \| Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Hedged items	69		277
Interest rate contracts and Foreign currency contracts	(76)		(286)
Interest Expense [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts	3		7
Interest Expense [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts and Foreign currency contracts	(13)		(22)
Interest Expense [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Interest rate contracts	(1)		5
Foreign currency derivatives	$ (13)		$ (20)