Long-Term Borrowings and Capital Lease Obligations (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended																													1 Months Ended															1 Months Ended																	1 Months Ended
	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Medium-term notes due 2013-2041 [Member]		Dec. 31, 2010 Medium-term notes due 2013-2041 [Member]		Dec. 31, 2011 4.75% notes due 2012 [Member]		Dec. 31, 2010 4.75% notes due 2012 [Member]		Dec. 31, 2011 5.00% notes due 2013, Note 1 [Member]	Dec. 31, 2010 5.00% notes due 2013, Note 1 [Member]	Dec. 31, 2011 5.00% notes due 2013, Note 2 [Member]	Dec. 31, 2010 5.00% notes due 2013, Note 2 [Member]	Dec. 31, 2011 Senior Note 1 Point 75 Percent Due 2014, Note [Member] [Member]	Dec. 31, 2010 Senior Note 1 Point 75 Percent Due 2014, Note [Member] [Member]	Dec. 31, 2011 5.875% notes due 2014 [Member]	Dec. 31, 2010 5.875% notes due 2014 [Member]	Dec. 31, 2011 4.875% notes due 2014 [Member]	Dec. 31, 2010 4.875% notes due 2014 [Member]	Dec. 31, 2011 3.25% notes due 2015 [Member]		Dec. 31, 2010 3.25% notes due 2015 [Member]		Dec. 31, 2011 4.75% notes due 2015 [Member]	Dec. 31, 2010 4.75% notes due 2015 [Member]	Dec. 31, 2011 1.95% notes due 2016 [Member]	Dec. 31, 2010 1.95% notes due 2016 [Member]	Mar. 31, 2011 Senior Note 2 Point 75 Percent Due 2016 [Member]	Dec. 31, 2011 Senior Note 2 Point 75 Percent Due 2016 [Member]	Dec. 31, 2010 Senior Note 2 Point 75 Percent Due 2016 [Member]	Dec. 31, 2011 5.25% notes due 2016 [Member]	Dec. 31, 2010 5.25% notes due 2016 [Member]	Dec. 31, 2011 6.00% notes due 2018 [Member]		Dec. 31, 2010 6.00% notes due 2018 [Member]		Dec. 31, 2011 5.75% notes due 2019 [Member]	Dec. 31, 2010 5.75% notes due 2019 [Member]	Dec. 31, 2011 4.625% notes due 2020 [Member]	Dec. 31, 2010 4.625% notes due 2020 [Member]	Dec. 31, 2011 3.625% notes due 2021 [Member]	Dec. 31, 2010 3.625% notes due 2021 [Member]	Mar. 31, 2011 Senior Note 4 Point 25 Percent Due 2021 [Member]	Dec. 31, 2011 Senior Note 4 Point 25 Percent Due 2021 [Member]	Dec. 31, 2010 Senior Note 4 Point 25 Percent Due 2021 [Member]	Dec. 31, 2011 6.50% debentures due 2028 [Member]	Dec. 31, 2010 6.50% debentures due 2028 [Member]	Dec. 31, 2011 5.60% notes due 2036 [Member]	Dec. 31, 2010 5.60% notes due 2036 [Member]	Dec. 31, 2011 4.90% notes due 2041 [Member]	Dec. 31, 2010 4.90% notes due 2041 [Member]	Dec. 31, 2011 Other Loans [Member]		Dec. 31, 2010 Other Loans [Member]		Dec. 31, 2011 Other Loans, Various Currencies [Member]		Dec. 31, 2010 Other Loans, Various Currencies [Member]		Mar. 31, 2011 Senior Note 1 Point 75 Percent Due 2014 [Member]	Dec. 31, 2011 Floating Rate Senior Note Due 2014 [Member]		Mar. 31, 2011 Floating Rate Senior Note Due 2014 [Member]	Dec. 31, 2010 Floating Rate Senior Note Due 2014 [Member]		Dec. 31, 2011 Interest Rate Swap [Member]	Dec. 31, 2010 Interest Rate Swap [Member]	Dec. 31, 2008 Interest Rate Swap [Member]
Debt Instrument [Line Items]
Medium-term notes				$ 401	[1]	$ 420	[1]
Senior Notes								400	[2]	400	[2]	250	250	747	746	400	0	170	170	499	498	1,065	[3]	1,038	[3]	399	399	496	495	500	499	0	599	599	1,405	[4]	1,425	[4]	499	498	997	996	999	999	500	499	0			395	395	493	493									400	600	[5]	600	0	[5]
Debenture notes																																																299	299
Other loans																																																						8	[2]	9	[2]	4	[2]	8	[2]
Total long-term debt		12,123	10,137
Less short-term portion of long-term debt		410	4
Total long-term debt less current maturities		11,713	10,133
Capital lease obligations		23	4
Total long-term debt and capital lease obligations		11,736	10,137
Average interest rate on medium-term notes		3.70%	3.40%
Interest rate on long-term debt																																																															1.00%
Notional amounts on interest rate swap agreements																																																																				1,000	1,000
Fair value of interest rate swaps, asset																																																																				66	40
Effective yield of interest rate swap																																																																						3.85%
Debt instrument, stated rate								4.75%				5.00%		5.00%		1.75%		5.875%		4.875%		3.25%				4.75%		1.95%		2.75%	2.75%		5.25%		6.00%				5.75%		4.625%		3.625%		4.25%	4.25%		6.50%		5.60%		4.90%		2.00%								1.75%
Debt instrument maturity date																														2016															2021																	2014
Spread on floating rate debt																																																																	0.42%
Net proceeds from issuance of debt	1,991
Maturities of long-term borrowings, year 2		1,245
Maturities of long-term borrowings, year 3		1,669
Maturities of long-term borrowings, year 4		1,465
Maturities of long-term borrowings, year 5		1,594
Maturities of long-term borrowings, thereafter		5,740
Fair value of long-term borrowings		$ 13,050	$ 10,800

[1] Average interest rates on medium-term notes at December 31, 2011 and 2010 were 3.7% and 3.4%, respectively.

[2] Includes long-term debt due within one year.

[3] At December 31, 2011 and 2010, the company had outstanding interest rate swap agreements with gross notional amounts of $1,000. Over the remaining terms of the notes, the company will receive fixed payments equivalent to the underlying debt and pay floating payments based on USD LIBOR (London Interbank Offered Rate) . The fair value of outstanding swaps was an asset of $66 and $40 at December 31, 2011 and 2010, respectively.

[4] During 2008, the interest rate swap agreement associated with these notes was terminated. The gain will be amortized over the remaining life of the bond, resulting in an effective yield of 3.85%.

[5] Interest rate on floating rate notes at December 31, 2011 was 1.0%.