Derivative Instruments and Hedging Activities - Part 2 (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Assets
Derivative Assets, Gross	$ 412	$ 375
Liabilities
Derivative Liabilities, Gross	607	490
Derivative, net liability position, present value	68	58
Collateral Already Posted, Aggregate Fair Value	40	38
Other Current Assets [Member]
Assets
Derivative Assets, Gross	92	86
Other Current Liabilities [Member]
Liabilities
Derivative Liabilities, Gross	145	144
Other Noncurrent Assets [Member]
Assets
Derivative Assets, Gross	320	289
Other Noncurrent Liabilities [Member]
Liabilities
Derivative Liabilities, Gross	462	346
Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	51	38
Liabilities
Derivative Liabilities, Gross	543	448
Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	361	337
Liabilities
Derivative Liabilities, Gross	64	42
Interest Rate Contract [Member]
Liabilities
Derivative Liabilities, Gross	464	358
Interest Rate Contract [Member] | Designated as Hedging Instruments [Member]
Liabilities
Derivative Liabilities, Gross	464	358
Interest Rate Contract [Member] | Not Designated as Hedging Instruments [Member]
Liabilities
Derivative Liabilities, Gross	0	0
Cross currency derivatives [Member]
Liabilities
Derivative Liabilities, Gross	33	43
Cross currency derivatives [Member] | Designated as Hedging Instruments [Member]
Liabilities
Derivative Liabilities, Gross	33	43
Cross currency derivatives [Member] | Not Designated as Hedging Instruments [Member]
Liabilities
Derivative Liabilities, Gross	0	0
Foreign Exchange Contract [Member]
Assets
Derivative Assets, Gross	341	327
Liabilities
Derivative Liabilities, Gross	60	56
Foreign Exchange Contract [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	14	8
Liabilities
Derivative Liabilities, Gross	35	35
Foreign Exchange Contract [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	327	319
Liabilities
Derivative Liabilities, Gross	25	21
Commodity Contract [Member]
Assets
Derivative Assets, Gross	71	48
Liabilities
Derivative Liabilities, Gross	50	33
Commodity Contract [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	37	30
Liabilities
Derivative Liabilities, Gross	11	12
Commodity Contract [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	34	18
Liabilities
Derivative Liabilities, Gross	$ 39	$ 21