Long-term Debt (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Summary of Long-Term Debt
Long-term debt, carrying amount	$ 8,730	$ 5,504
Fair value adjustment-hedging	10	13
Other Long-term Debt, Noncurrent, Total	8,740	5,517
3.30% Senior Notes due 2021 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	1,595	0
4.50% Guaranteed Notes due 2014 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	1,364	1,319
2.75% Guaranteed Notes due 2015 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	1,357	1,310
1.95% Senior Notes due 2016 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	1,099	0
4.20% Guaranteed Notes due 2021 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	1,099	0
5.25% Guaranteed Notes due 2013 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	682	659
2.65% Guaranteed Notes due 2016 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	498	0
3.00% Guaranteed Notes due 2013 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	450	450
Floating Rate Senior Notes due 2014 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	299	0
9.75% Senior Notes due 2019 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	0	776
8.625% Senior Notes due 2014 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	0	272
6.00% Senior Notes due 2016 [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	0	218
Commercial Paper [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	0	367
Debt, Other [Member]
Summary of Long-Term Debt
Long-term debt, carrying amount	$ 287	$ 133