Debt and Capital Lease Obligations (Details) (USD $) In Millions, unless otherwise specified					12 Months Ended												12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Bank Credit Facilities [Member]	Dec. 31, 2011 Bank Credit Facilities [Member]	Dec. 31, 2012 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Apr. 30, 2012 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Mar. 31, 2012 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Dec. 31, 2011 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Apr. 30, 2011 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Apr. 30, 2010 Tax Exempt Revenue Refunding Bonds Series 1997A [Member]	Dec. 31, 2011 Tax Exempt Revenue Refunding Bonds Series 1997B [Member]	Apr. 30, 2011 Tax Exempt Revenue Refunding Bonds Series 1997B [Member]	Apr. 30, 2010 Tax Exempt Revenue Refunding Bonds Series 1997B [Member]	Dec. 31, 2011 Tax Exempt Revenue Refunding Bonds Series 1997C [Member]	Apr. 30, 2011 Tax Exempt Revenue Refunding Bonds Series 1997C [Member]	Apr. 30, 2010 Tax Exempt Revenue Refunding Bonds Series 1997C [Member]	Dec. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1997 [Member]	Mar. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1997 [Member]	Dec. 31, 2011 Tax Exempt Waste Disposal Revenue Bonds Series 1997 [Member]	Dec. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1998 [Member]	Mar. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1998 [Member]	Dec. 31, 2011 Tax Exempt Waste Disposal Revenue Bonds Series 1998 [Member]	Dec. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1999 [Member]	Mar. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 1999 [Member]	Dec. 31, 2011 Tax Exempt Waste Disposal Revenue Bonds Series 1999 [Member]	Dec. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 2001 [Member]	Mar. 31, 2012 Tax Exempt Waste Disposal Revenue Bonds Series 2001 [Member]	Dec. 31, 2011 Tax Exempt Waste Disposal Revenue Bonds Series 2001 [Member]	Dec. 31, 2012 Notes Due In February 2015 [Member]	Dec. 31, 2011 Notes Due In February 2015 [Member]	Feb. 28, 2010 Notes Due In February 2015 [Member]	Dec. 31, 2012 Notes Due In 2013 [Member]	Dec. 31, 2011 Notes Due In 2013 [Member]	Dec. 31, 2012 Notes Due In 2014 [Member]	Dec. 31, 2011 Notes Due In 2014 [Member]	Dec. 31, 2012 Notes Due In 2017 [Member]	Dec. 31, 2011 Notes Due In 2017 [Member]	Dec. 31, 2012 Notes Due In February 2020 [Member]	Dec. 31, 2011 Notes Due In February 2020 [Member]	Feb. 28, 2010 Notes Due In February 2020 [Member]	Dec. 31, 2012 Notes Due In 2037 [Member]	Dec. 31, 2011 Notes Due In 2037 [Member]	Dec. 31, 2012 Notes Due In 2012 [Member]	Apr. 30, 2012 Notes Due In 2012 [Member]	Dec. 31, 2011 Notes Due In 2012 [Member]	Dec. 31, 2012 Notes Due In 2032 [Member]	Dec. 31, 2011 Notes Due In 2032 [Member]	Dec. 31, 2012 Notes Due In 2030 [Member]	Dec. 31, 2011 Notes Due In 2030 [Member]	May 31, 2011 Senior Notes Due In May 2011 [Member]	Dec. 31, 2012 Debenture Due In 2026 [Member]	Dec. 31, 2011 Debenture Due In 2026 [Member]	Dec. 31, 2012 Debenture Due In 2015 [Member]	Dec. 31, 2011 Debenture Due In 2015 [Member]	Dec. 31, 2012 Senior Notes Due In 2013 [Member]	Dec. 31, 2011 Senior Notes Due In 2013 [Member]	Feb. 28, 2011 Senior Notes Due In February 2011 [Member]	Dec. 31, 2012 Senior Notes Due In 2037 [Member]	Dec. 31, 2011 Senior Notes Due In 2037 [Member]	Dec. 31, 2012 Senior Notes Due In 2017 [Member]	Dec. 31, 2011 Senior Notes Due In 2017 [Member]	Dec. 31, 2012 Senior Notes Due In 2097 [Member]	Dec. 31, 2011 Senior Notes Due In 2097 [Member]	Dec. 31, 2012 Senior Notes Due In March 2019 [Member]	Dec. 31, 2011 Senior Notes Due In March 2019 [Member]	Dec. 31, 2012 Senior Notes Due In March 2039 [Member]	Dec. 31, 2011 Senior Notes Due In March 2039 [Member]	Dec. 31, 2012 Gulf Opportunity Zone Revenue Bonds Series 2010 [Member]	Jun. 30, 2012 Gulf Opportunity Zone Revenue Bonds Series 2010 [Member]	Dec. 31, 2011 Gulf Opportunity Zone Revenue Bonds Series 2010 [Member]	Dec. 31, 2012 Other Debt [Member]	Dec. 31, 2011 Other Debt [Member]
Debt Instruments
Debt instruments maturity date (year)					2027												2031			2032			2032			2032			2015			2013		2014		2017		2020			2037		2012			2032		2030			2026		2015		2013			2037		2017		2097		2019		2039		2040			2013
Bank credit facilities			$ 0	$ 0
Industrial revenue bond					0			18									0		25	0		25	0		25	0		19
Other notes payable																													400	400		300	300	200	200	750	750	850	850		1,500	1,500	0		750	750	750	200	200
Debentures																																																			100	100	75	75
Senior notes																																																							180	180		24	24	200	200	100	100	750	750	250	250
Revenue bond																																																																				300		0
Accounts receivable sales facility																																																																							100	250
Net unamortized discount, including fair value adjustments	(29)	(51)
Total debt	7,000	7,690
Capital lease obligations, including unamortized fair value adjustments	49	51
Total debt and capital lease obligations	7,049	7,741
Less current portion	(586)	(1,009)
Debt and capital lease obligations, less current portion	$ 6,463	$ 6,732
Interest rate of notes in percentage					5.45%	5.45%	5.45%		5.45%	5.45%	5.40%	5.40%	5.40%	5.40%	5.40%	5.40%	5.60%	5.60%		5.60%	5.60%		5.70%	5.70%		6.65%	6.65%		4.50%		4.50%	4.75%		4.75%		6.125%		6.125%		6.125%	6.625%		6.875%	6.875%		7.50%		8.75%		6.125%	7.65%		8.75%		6.70%		6.75%	6.75%		7.20%		7.45%		9.375%		10.50%		4.00%	4.00%