Debt (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended				3 Months Ended									3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Senior Notes Payable Due 2014 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2014 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2015 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2015 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2016 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2016 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2018 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2018 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2021 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2021 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2022 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2022 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2023 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2023 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2038 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2038 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2041 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2041 [Member]	Mar. 31, 2014 Senior Notes Payable Due 2043 [Member]	Dec. 31, 2013 Senior Notes Payable Due 2043 [Member]	Mar. 31, 2014 Senior Notes Payable [Member]	Dec. 31, 2013 Senior Notes Payable [Member]	Mar. 31, 2014 Commercial Paper [Member]	Dec. 31, 2013 Commercial Paper [Member]	Mar. 31, 2014 Other Debt [Member]	Dec. 31, 2013 Other Debt [Member]	Mar. 31, 2014 Obligations Under Capital Leases [Member]	Dec. 31, 2013 Obligations Under Capital Leases [Member]	Mar. 31, 2014 Amended Line of Credit [Member]	Mar. 31, 2014 Line of Credit Multi Currency [Member]	Apr. 11, 2014 Line of Credit Multi Currency [Member] Subsequent Event [Member]	Mar. 31, 2014 New Line Of Credit Multi Currency [Member] Subsequent Event [Member]	Apr. 11, 2014 New Line Of Credit Multi Currency [Member] Subsequent Event [Member]	Mar. 31, 2014 Letter of Credit [Member] Subsequent Event [Member]
Debt Instrument [Line Items]
Principal outstanding, net of unamortized discount	$ 3,189.8	$ 2,859.8	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 450.0	$ 450.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0	$ 300.0	$ 300.0	$ 250.0	$ 250.0	$ 250.0	$ 250.0			$ 325.0	$ 0	$ 62.3	$ 56.6	$ 59.3	$ 60.2
Unamortized original issue discount																							(6.8)	(7.0)
Current maturities	(626.7)	(297.0)
Long-term maturities	2,563.1	2,562.8
Maturity date			Jun. 02, 2014		Apr. 30, 2015		Dec. 15, 2016		Jul. 15, 2018		Jun. 01, 2021		Apr. 30, 2022		Dec. 15, 2023		Jul. 15, 2038		Jun. 01, 2041		Dec. 15, 2043													Apr. 11, 2017
Interest rate (in hundredths)					1.60%	1.60%	1.15%	1.15%	6.375%	6.375%	4.50%	4.50%	3.60%	3.60%	4.00%	4.00%	7.00%	7.00%	5.95%	5.95%	5.125%	5.125%
Weighted average interest rate (in hundredths)																									0.30%
Number of days in which commercial paper matures																									364 days
Letters of credit outstanding																																122.0	31.7		92.4
Maximum borrowing capacity																									500.0						835.0	170.0	40.0	750.0		200.0
Remaining capacity under revolving line of credit facility																																$ 48.0			$ 657.6
Term of revolving credit facility																																		3 years