Debt Financing Arrangements (Narrative) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	6 Months Ended		12 Months Ended											0 Months Ended	1 Months Ended	6 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2013 Debentures four point four seven nine percent due in two thousand twenty one [Member]	Dec. 31, 2013 Debentures five point four five percent due in two thousand eighteen [Member]	Dec. 31, 2013 Debentures five point seven six five percent due in two thousand forty one [Member]	Dec. 31, 2013 Debentures five point three seven five percent due in two thousand thirty five [Member}	Dec. 31, 2013 Debentures five point nine three five percent due in two thousand thirty two [Member]	Dec. 31, 2013 Debentures four point zero one six percent due in two thousand forty three [Member]	Oct. 31, 2012 Debentures four point zero one six percent due in two thousand forty three [Member]	Dec. 31, 2013 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Feb. 28, 2007 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Dec. 31, 2012 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Dec. 31, 2011 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Dec. 31, 2013 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Dec. 31, 2012 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Jun. 30, 2012 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Jun. 30, 2011 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Jun. 30, 2007 Convertible senior notes point eight seven five percent due two thousand fourteen [Member]	Dec. 31, 2013 Debentures eight point three seven five percent due in two thousand seventeen [ Member]	Dec. 31, 2013 Debentures seven point one two five percent due in two thousand thirteen [Member]	Dec. 31, 2013 Debentures seven point five percent due in two thousand twenty seven [Member]	Dec. 31, 2013 Debentures four point five three five percent due in two thousand forty two [Member]	Dec. 31, 2013 Debentures seven percent due in two thousand thirty one [Member]	Dec. 31, 2013 Debentures six point six two five percent due in two thousand twenty nine [Member]	Dec. 31, 2013 Debentures six point nine five due in two thousand ninety seven [Member]	Dec. 31, 2013 Debentures six point four five percent due in two thousand thirty eight [Member]	Dec. 31, 2013 Debentures six point seven five percent due in two thousand twenty seven [Member]	Dec. 31, 2013 Lines of credit [Member]	Dec. 31, 2012 Lines of credit [Member]	Dec. 31, 2013 Commercial Paper [Member]
Debt And Financing Arrangements [Line Items]
Debt face amount exchanged for new debentures													$ 570,000,000
Interest rate stated percentage		4.70%					4.479%	5.45%	5.765%	5.375%	5.935%	4.016%		0.875%	0.875%			0.875%					8.375%	7.125%	7.50%	4.535%	7.00%	6.625%	6.95%	6.45%	6.75%
Debt instrument, maturity year							2021	2018	2041	2035	2032	2043			2014			2014					2017	2013	2027	2042	2031	2029	2097	2038	2027
Proceeds from long-term debt borrowings	106,000,000	91,000,000	23,000,000	112,000,000	97,000,000	1,564,000,000									1,150,000,000
Debt premium													196,000,000
Charges from early extinguishment of debt	5,000,000	12,000,000	0	5,000,000	12,000,000	15,000,000
Debt Instrument, Maturity Date																		Jan. 15, 2014
Convertible debt initial conversion units														22.8423
Principal amount of debt used for conversion ratio														1,000				1,000
Convertible debt conversion price (in dollars per share)														$ 43.78				$ 43.78
Minimum number of days within a specified consecutive trading day period in which the closing price of the entity's common stock must exceed the conversion price by a specified percentage rate for the notes to be redeemable (in days)																		20 days
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price by a specified rate for a minimum amount of days in order for the notes to be redeemable (in days)																		30 days
Percentage of the closing sales price of the entity's common stock that the conversion price must exceed in order for the notes to be convertible (as a percent)																		140.00%
Maximum amount of cash that holder would receive upon conversion														1,000				1,000
Number of consecutive business days immediately after any specified consecutive trading day period																		5 days
Number of consecutive trading days immediately prior to specified number of consecutive business days																		5 days
Maximum percentage rate of the average product of the closing price of the Company's common stock and the average conversion rate of the debt instrument that the average trading price must be equal to or less than in order for the debt instruments to be convertible.																		98.00%
Percentage of principal amount plus accrued and unpaid interest at which holders may require the entity to repurchase the debt instrument														100.00%				100.00%
Proceeds from notes recorded as long-term debt																						853,000,000
Proceeds from notes recorded as equity																						297,000,000
Discount amortization expense included in interest expense related to the notes	23,000,000	26,000,000	54,000,000	46,000,000	49,000,000	50,000,000						2,000,000				24,000,000	22,000,000	49,000,000	47,000,000	45,000,000	43,000,000
Purchased call options with issuance of notes																						300,000,000
Sale of warrants (in shares)																						26.3
Excercise price of warrants (per share)																						$ 62.56
Conversion price of warrants (in dollars per share)																						$ 62.56
Proceeds from sale of warrants																						170,000,000
Net cost of purchased call options and warrants																						130,000,000
Excess of fair value over carrying value of long-term debt			900,000,000
Maturities of long-term debt due 2013			1,200,000,000
Maturities of long-term debt due 2014			19,000,000
Maturities of long-term debt due 2015			15,000,000
Maturities of long-term debt due 2016			305,000,000
Maturities of long-term debt due 2017			709,000,000
Lines of credit																																6,900,000,000		4,000,000,000
Unused lines of credit																																6,600,000,000
Weighted average interest rate on short term borrowings (as a percent)																																4.24%	0.70%
Outstanding standby letters of credit and surety bonds	911,000,000		795,000,000	911,000,000
Maximum amount provided under accounts receivable securitization facility excluded in lines of credit			1,100,000,000
Amount utilized from the securitization facility			$ 1,100,000,000