Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 18.2		$ 18.2
Short-term borrowings	23.6		49.2
Long-Term Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	$ 275.0		275.0
Debt Instrument, Interest Rate, Stated Percentage	4.40%
Minimum [Member]
Line of Credit Facility [Line Items]
Description of Variable Rate Basis	LIBOR
Basis spread on variable rate (in hundredths)	1.00%
Maximum [Member]
Line of Credit Facility [Line Items]
Description of Variable Rate Basis	LIBOR
Basis spread on variable rate (in hundredths)	2.05%
Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 2,000.0
Outstanding borrowings on the revolving credit facility	800.0		255.0
Average outstanding borrowings	$ 554.3	$ 158.0
Pricing on the Facility based on market rates	LIBOR plus 1.00% to 2.05%
Description of Variable Rate Basis	LIBOR
Basis spread on variable rate (in hundredths)	1.00%
Line of credit, interest rate during period	1.40%	1.10%
Covenant Terms Minimum Leverage Ratio Through Specified Date Following a Material Acquisition	400.00%
Covenant terms, minimum cash interest coverage ratio	300.00%
Overdraft Facilities [Member]
Line of Credit Facility [Line Items]
Borrowing capacity remaining	$ 43.0
Bank Overdrafts	$ 18.6		$ 24.6