Debt and Other Financing (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Mar. 31, 2009	Mar. 31, 2008	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2003	Jan. 31, 2006 Five Point One Two Five Percent Notes, Due January Two Thousand Eleven [Member]	Dec. 31, 2011 Four Point Eight Percent Notes, Due March Two Thousand Thirteen [Member]	Dec. 31, 2010 Four Point Eight Percent Notes, Due March Two Thousand Thirteen [Member]	Mar. 31, 2008 Four Point Eight Percent Notes, Due March Two Thousand Thirteen [Member]	Dec. 31, 2011 Four Point Six Two Five Percent Notes, Due May Two Thousand Thirteen [Member]	Dec. 31, 2010 Four Point Six Two Five Percent Notes, Due May Two Thousand Thirteen [Member]	May 31, 2003 Four Point Six Two Five Percent Notes, Due May Two Thousand Thirteen [Member]	Dec. 31, 2011 Five Point Six Two Five Percent Notes, Due March Two Thousand Fourteen [Member]	Dec. 31, 2010 Five Point Six Two Five Percent Notes, Due March Two Thousand Fourteen [Member]	Mar. 31, 2009 Five Point Six Two Five Percent Notes, Due March Two Thousand Fourteen [Member]	Nov. 23, 2010 Two Point Six Percent Notes, Due November Two Thousand Fifteen [Member]	Dec. 31, 2011 Five Point Seven Five Percent Notes, Due March Two Thousand Eighteen [Member]	Dec. 31, 2010 Five Point Seven Five Percent Notes, Due March Two Thousand Eighteen [Member]	Mar. 31, 2008 Five Point Seven Five Percent Notes, Due March Two Thousand Eighteen [Member]	Dec. 31, 2011 Four Point Two Percent Notes, Due July Two Thousand Eighteen [Member]	Dec. 31, 2010 Four Point Two Percent Notes, Due July Two Thousand Eighteen [Member]	Jun. 30, 2003 Four Point Two Percent Notes, Due July Two Thousand Eighteen [Member]	Dec. 31, 2011 Six Point Five Percent Notes, Due March Two Thousand Nineteen [Member]	Dec. 31, 2010 Six Point Five Percent Notes, Due March Two Thousand Nineteen [Member]	Mar. 31, 2009 Six Point Five Percent Notes, Due March Two Thousand Nineteen [Member]	Nov. 23, 2010 Four Point Zero Three Percent Notes, Due November Two Thousand Twenty [Member]	Nov. 23, 2010 Four Point One Eight Percent Notes, Due November Two Thousand Twenty Two [Member]	Dec. 31, 2011 Line of Credit [Member]	Dec. 31, 2011 Private Placement Notes [Member]
Debt Instrument, Unamortized Discount (Premium), Net										$ 3.7	$ 6.3
Average annual interest rates			10.90%	5.60%
Bank overdrafts			17.4	58.2
Obligations under capital leases			19.0	15.2
Net unrealized gains on debt with fair value hedges			147.6	94.4
Principal Amount of Debt	850.0	500.0			100.0	500.0			250.0			125.0			500.0	142.0			250.0			250.0			350.0	290.0	103.0
Minimum compliance of interest coverage ratio, numerator																												4	4
Minimum compliance of interest coverage ratio, denominator																												1	1
Net proceeds used to repay outstanding debt	837.6	496.3
Unamortized discount to face value							0.1	0.2					1.2	1.7			0.5	0.6		0.5	0.6		3.1	3.6
Debt purchase price percentage of aggregate principal amount			101.00%
Interest rate, stated percentage					6.25%	5.125%			4.80%			4.625%			5.625%	2.60%			5.75%			4.20%			6.50%	4.03%	4.18%
Debt issued for cash					4.0
Revolving credit and competitive advance facility			1,000.0
Commercial Paper			709.0
Commercial Paper Program			1,000.0
Credit facility, interest rate terms			The Credit Facility also allows for borrowing at an interest rate based on the CDS Spread minus 1%, but not less than 0% per annum, plus the highest of prime, .5% plus the federal funds rate, or 1% plus one month LIBOR.
Credit facility annual fee			1.7
Revolving Line of Credit Incremental Principal Amount			250.0
Letters of credit outstanding			23.4	16.4
Future Minimum Sublease Rentals, Sale Leaseback Transactions			$ 58.5	$ 65.5
Percentage of Debt Hedged by Interest Rate Derivatives			74.00%	74.00%