Long-Term Debt and Other Financing Arrangements (Details) (USD $)				6 Months Ended
	Feb. 16, 2011	Jun. 30, 2011 Notes 4.75% Due 2021 [Member]	Jun. 30, 2011 Debentures 6.25% Due 2041 [Member]	Jun. 30, 2011 Three-Year Revolving Credit Facility [Member] years	Jun. 30, 2011 Five-Year Revolving Credit Facility [Member] years	Jun. 30, 2011 Revolving Credit Facilities [Member]	Jun. 30, 2011 Revolving Facilities Does Not Exceed Twenty Five Percent [Member]	Jun. 30, 2011 Revolving Facilities Exceeds Twenty Five Percent [Member]
Debt Instrument [Abstract]
Debt instrument, face amount		$ 1,000,000,000	$ 1,000,000,000
Debt instrument, interest rate, stated percentage		4.75%	6.25%
Line Of Credit Facility Abstract
Line Of Credit Facility Maximum Borrowing Capacity				2,500,000,000	2,500,000,000	5,000,000,000
Line of credit facility, term of facility in years				3	5
Line of credit facility, interest rate during period based on LIBOR percent							1.25%	1.50%
Line of credit facility, percentage of commitments used							25.00%	25.00%
Line of credit facility, commitment fee percent				0.225%	0.30%
Line of credit facility, maximum letters of credit issuance						500,000,000
Line of credit facility, maximum leverage ratio						4.5
Line of credit facility, maximum borrowing capacity amount of potential increase						500,000,000
Unsecured commercial paper program, maximum borrowing capacity	$ 5,000,000,000