Long-Term Borrowings and Capital Lease Obligations (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2012 Medium-term notes due 2013-2041 [Member]		Dec. 31, 2011 Medium-term notes due 2013-2041 [Member]		Dec. 31, 2012 4.75% notes due 2012 [Member]		Dec. 31, 2011 4.75% notes due 2012 [Member]		Dec. 31, 2012 5.00% notes due 2013, Note 1 [Member]		Dec. 31, 2011 5.00% notes due 2013, Note 1 [Member]		Dec. 31, 2012 5.00% notes due 2013, Note 2 [Member]		Dec. 31, 2011 5.00% notes due 2013, Note 2 [Member]		Dec. 31, 2012 5.875% notes due 2014 [Member]	Dec. 31, 2011 5.875% notes due 2014 [Member]	Dec. 31, 2012 1.75% notes due 2014 [Member]	Dec. 31, 2011 1.75% notes due 2014 [Member]	Dec. 31, 2012 Floating rate notes due 2014 [Member]		Dec. 31, 2011 Floating rate notes due 2014 [Member]		Dec. 31, 2012 4.875% notes due 2014 [Member]	Dec. 31, 2011 4.875% notes due 2014 [Member]	Dec. 31, 2012 3.25% notes due 2015 [Member]		Dec. 31, 2011 3.25% notes due 2015 [Member]		Dec. 31, 2012 3.25% notes due 2015 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 3.25% notes due 2015 [Member] Interest Rate Swap [Member]	Dec. 31, 2012 4.75% notes due 2015 [Member]	Dec. 31, 2011 4.75% notes due 2015 [Member]	Dec. 31, 2012 1.95% notes due 2016 [Member]	Dec. 31, 2011 1.95% notes due 2016 [Member]	Dec. 31, 2012 2.75% notes due 2016 [Member]	Dec. 31, 2011 2.75% notes due 2016 [Member]	Dec. 31, 2012 5.25% notes due 2016 [Member]	Dec. 31, 2011 5.25% notes due 2016 [Member]	Dec. 31, 2012 6.00% notes due 2018 [Member]		Dec. 31, 2011 6.00% notes due 2018 [Member]		Dec. 31, 2008 6.00% notes due 2018 [Member] Interest Rate Swap [Member]	Dec. 31, 2012 5.75% notes due 2019 [Member]	Dec. 31, 2011 5.75% notes due 2019 [Member]	Dec. 31, 2012 4.625% notes due 2020 [Member]	Dec. 31, 2011 4.625% notes due 2020 [Member]	Dec. 31, 2012 3.625% notes due 2021 [Member]	Dec. 31, 2011 3.625% notes due 2021 [Member]	Dec. 31, 2012 4.25% notes due 2021 [Member]	Dec. 31, 2011 4.25% notes due 2021 [Member]	Dec. 31, 2012 6.50% debentures due 2028 [Member]	Dec. 31, 2011 6.50% debentures due 2028 [Member]	Dec. 31, 2012 5.60% notes due 2036 [Member]	Dec. 31, 2011 5.60% notes due 2036 [Member]	Dec. 31, 2012 4.90% notes due 2041 [Member]	Dec. 31, 2011 4.90% notes due 2041 [Member]	Dec. 31, 2012 Other Loans [Member]		Dec. 31, 2011 Other Loans [Member]		Dec. 31, 2012 Other Loans, Various Currencies [Member]		Dec. 31, 2011 Other Loans, Various Currencies [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage									4.75%		4.75%		5.00%		5.00%		5.00%		5.00%		5.875%	5.875%	1.75%	1.75%					4.875%	4.875%	3.25%		3.25%				4.75%	4.75%	1.95%	1.95%	2.75%	2.75%	5.25%	5.25%	6.00%		6.00%			5.75%	5.75%	4.625%	4.625%	3.625%	3.625%	4.25%	4.25%	6.50%	6.50%	5.60%	5.60%	4.90%	4.90%
Medium-term notes					$ 374	[1],[2]	$ 401	[1],[2]
Senior notes									0	[1]	400	[1]	250	[1]	250	[1]	749	[1]	747	[1]	170	170	400	400	600	[3]	600	[3]	499	499	1,054	[4]	1,065	[4]			400	399	497	496	499	499	599	599	1,383	[5]	1,405	[5]		499	499	997	997	999	999	499	499			395	395	493	493
Debenture notes																																																										299	299
Other loans																																																																36	[1]	8	[1]	2	[1]	4	[1]
Total long-term debt	11,693	12,123
Less short-term portion of long-term debt	1,252	410
Total long-term debt less current maturities	10,441	11,713
Capital lease obligations	24	23
Total long-term debt and capital lease obligations	10,465	11,736
Average interest rate					4.00%		3.70%																																																									3.90%		3.90%
Interest rate on long-term debt																									0.70%		1.00%
Notional amount of interest rate swaps																																			1,000	1,000
Fair value of interest rate swaps, asset																																			55	66
Effective yield of interest rate swap																																																	3.85%
Maturities of long-term borrowings, 2014	1,669
Maturities of long-term borrowings, 2015	1,455
Maturities of long-term borrowings, 2016	1,596
Maturities of long-term borrowings, 2017	0
Maturities of long-term borrowings, thereafter	5,721
Fair value of long-term borrowings			$ 11,715	$ 13,050

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

[2] Average interest rates on medium-term notes at December 31, 2012 and 2011 were 4.0% and 3.7%, respectively.

[3] Interest rate on floating rate notes at December 31, 2012 and 2011 was 0.7% and 1.0%, respectively.

[4] At December 31, 2012 and 2011, 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 $55 and $66 at December 31, 2012 and 2011, respectively.

[5] 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%.