Derivative Instruments and Hedging Activities - Part 2 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Derivative Assets, Gross	$ 192	$ 240
Liabilities
Derivative Liabilities, Gross	491	371
Subject to netting arrangement [Member]
Assets
Derivative Assets, Gross	57	91
Derivative Assets Not Offset Under Netting Arrangements	(12)	(9)
Derivative Assets Not Offset By Collateral	0	(3)
Derivative Assets, Net	45	79
Liabilities
Derivative Liabilities, Gross	469	314
Derivative Liabilities Not Offset Under Netting Arrangements	(12)	(9)
Derivative Liabilities Not Offset By Collateral	(14)	(6)
Derivative Liabilities, Net	443	299
Current [Member]
Assets
Derivative Assets, Gross	65	32
Liabilities
Derivative Liabilities, Gross	165	157
Noncurrent [Member]
Assets
Derivative Assets, Gross	127	208
Liabilities
Derivative Liabilities, Gross	326	214
Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	48	113
Liabilities
Derivative Liabilities, Gross	462	351
Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	144	127
Liabilities
Derivative Liabilities, Gross	29	20
No longer carried at fair value [Member]
Assets
Derivative Assets, Gross	161	169
Liabilities
Derivative Liabilities, Gross	183	190
Interest rate derivatives [Member]
Assets
Derivative Assets, Gross	20	98
Liabilities
Derivative Liabilities, Gross	379	322
Interest rate derivatives [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	20	96
Liabilities
Derivative Liabilities, Gross	377	318
Interest rate derivatives [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	0	2
Liabilities
Derivative Liabilities, Gross	2	4
Cross currency derivatives [Member]
Assets
Derivative Assets, Gross	0	5
Liabilities
Derivative Liabilities, Gross	25	11
Cross currency derivatives [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	0	5
Liabilities
Derivative Liabilities, Gross	25	11
Cross currency derivatives [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	0	0
Liabilities
Derivative Liabilities, Gross	0	0
Foreign currency derivatives [Member]
Assets
Derivative Assets, Gross	131	113
Liabilities
Derivative Liabilities, Gross	53	21
Foreign currency derivatives [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	10	4
Liabilities
Derivative Liabilities, Gross	42	15
Foreign currency derivatives [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	121	109
Liabilities
Derivative Liabilities, Gross	11	6
Commodity derivatives [Member]
Assets
Derivative Assets, Gross	41	24
Liabilities
Derivative Liabilities, Gross	34	17
Commodity derivatives [Member] | Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	18	8
Liabilities
Derivative Liabilities, Gross	18	7
Commodity derivatives [Member] | Not Designated as Hedging Instruments [Member]
Assets
Derivative Assets, Gross	23	16
Liabilities
Derivative Liabilities, Gross	$ 16	$ 10