Derivative Instruments and Hedging Activities - Part 2 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Assets
Derivative Assets Current	$ 30	$ 49
Derivative Assets Noncurrent	96	71
Total assets	126	120
Liabilities
Derivative Liabilities Current	154	153
Total noncurrent derivative liabilities	690	537
Total liabilities	844	690
Level 1
Assets
Derivative Assets Current	0	2
Derivative Assets Noncurrent	0	0
Total assets	0	2
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Total liabilities	0	0
Level 2
Assets
Derivative Assets Current	20	40
Derivative Assets Noncurrent	22	12
Total assets	42	52
Liabilities
Derivative Liabilities Current	109	119
Total noncurrent derivative liabilities	376	357
Total liabilities	485	476
Level 3
Assets
Derivative Assets Current	10	7
Derivative Assets Noncurrent	74	59
Total assets	84	66
Liabilities
Derivative Liabilities Current	45	34
Total noncurrent derivative liabilities	314	180
Total liabilities	359	214
Designated as Hedging Instruments
Assets
Derivative Assets Current	5	12
Derivative Assets Noncurrent	16	4
Total assets	21	16
Liabilities
Derivative Liabilities Current	124	116
Total noncurrent derivative liabilities	505	442
Total liabilities	629	558
Not Designated as Hedging Instruments
Assets
Derivative Assets Current	25	37
Derivative Assets Noncurrent	80	67
Total assets	105	104
Liabilities
Derivative Liabilities Current	30	37
Total noncurrent derivative liabilities	185	95
Total liabilities	215	132
Interest Rate Derivatives
Assets
Derivative Assets Noncurrent	2	0
Liabilities
Derivative Liabilities Current	116	119
Total noncurrent derivative liabilities	523	440
Interest Rate Derivatives | Level 1
Assets
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Interest Rate Derivatives | Level 2
Assets
Derivative Assets Noncurrent	2	0
Liabilities
Derivative Liabilities Current	79	97
Total noncurrent derivative liabilities	263	334
Interest Rate Derivatives | Level 3
Assets
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	37	22
Total noncurrent derivative liabilities	260	106
Interest Rate Derivatives | Designated as Hedging Instruments
Assets
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	106	110
Total noncurrent derivative liabilities	500	425
Interest Rate Derivatives | Not Designated as Hedging Instruments
Assets
Derivative Assets Noncurrent	2	0
Liabilities
Derivative Liabilities Current	10	9
Total noncurrent derivative liabilities	23	15
Cross Currency Swaps
Assets
Derivative Assets Noncurrent	8	1
Liabilities
Derivative Liabilities Current	4	5
Total noncurrent derivative liabilities	2	14
Cross Currency Swaps | Level 1
Assets
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Cross Currency Swaps | Level 2
Assets
Derivative Assets Noncurrent	8	0
Liabilities
Derivative Liabilities Current	4	0
Total noncurrent derivative liabilities	2	0
Cross Currency Swaps | Level 3
Assets
Derivative Assets Noncurrent	0	1
Liabilities
Derivative Liabilities Current	0	5
Total noncurrent derivative liabilities	0	14
Cross Currency Swaps | Designated as Hedging Instruments
Assets
Derivative Assets Noncurrent	8	1
Liabilities
Derivative Liabilities Current	4	5
Total noncurrent derivative liabilities	2	14
Cross Currency Swaps | Not Designated as Hedging Instruments
Assets
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Foreign Currency
Assets
Derivative Assets Current	11	28
Derivative Assets Noncurrent	70	61
Liabilities
Derivative Liabilities Current	9	6
Total noncurrent derivative liabilities	113	20
Foreign Currency | Level 1
Assets
Derivative Assets Current	0	0
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Foreign Currency | Level 2
Assets
Derivative Assets Current	6	24
Derivative Assets Noncurrent	7	3
Liabilities
Derivative Liabilities Current	8	5
Total noncurrent derivative liabilities	106	10
Foreign Currency | Level 3
Assets
Derivative Assets Current	5	4
Derivative Assets Noncurrent	63	58
Liabilities
Derivative Liabilities Current	1	1
Total noncurrent derivative liabilities	7	10
Foreign Currency | Designated as Hedging Instruments
Assets
Derivative Assets Current	4	10
Derivative Assets Noncurrent	7	3
Liabilities
Derivative Liabilities Current	7	1
Total noncurrent derivative liabilities	0	0
Foreign Currency | Not Designated as Hedging Instruments
Assets
Derivative Assets Current	7	18
Derivative Assets Noncurrent	63	58
Liabilities
Derivative Liabilities Current	2	5
Total noncurrent derivative liabilities	113	20
Commodity & Other
Assets
Derivative Assets Current	19	21
Derivative Assets Noncurrent	16	9
Liabilities
Derivative Liabilities Current	25	23
Total noncurrent derivative liabilities	52	63
Commodity & Other | Level 1
Assets
Derivative Assets Current	0	2
Derivative Assets Noncurrent	0	0
Liabilities
Derivative Liabilities Current	0	0
Total noncurrent derivative liabilities	0	0
Commodity & Other | Level 2
Assets
Derivative Assets Current	14	16
Derivative Assets Noncurrent	5	9
Liabilities
Derivative Liabilities Current	18	17
Total noncurrent derivative liabilities	5	13
Commodity & Other | Level 3
Assets
Derivative Assets Current	5	3
Derivative Assets Noncurrent	11	0
Liabilities
Derivative Liabilities Current	7	6
Total noncurrent derivative liabilities	47	50
Commodity & Other | Designated as Hedging Instruments
Assets
Derivative Assets Current	1	2
Derivative Assets Noncurrent	1	0
Liabilities
Derivative Liabilities Current	7	0
Total noncurrent derivative liabilities	3	3
Commodity & Other | Not Designated as Hedging Instruments
Assets
Derivative Assets Current	18	19
Derivative Assets Noncurrent	15	9
Liabilities
Derivative Liabilities Current	18	23
Total noncurrent derivative liabilities	$ 49	$ 60