Debt - Short-Term and Long-Term Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Finance lease liabilities, current	$ 4.0
Finance lease liabilities, current		$ 4.4
Short-term debt and current portion of long-term debt	444.0	499.4
Finance lease liabilities, noncurrent	3.8
Finance lease liabilities, noncurrent		3.3
Syndicated revolving credit facility debt issuance costs	(1.9)	(2.1)
Long-term debt	2,652.4	2,651.6
Total debt	$ 3,096.4	3,151.0
4.125% Senior Note
Debt Instrument [Line Items]
Debt issuance date	Mar. 06, 2019
Debt maturity date	Mar. 15, 2029
Long-term debt	$ 613.5	613.9
Long term debt instrument interest rate stated percentage	4.125%
Unamortized discount on senior notes	$ (13.5)	(13.9)
4.000% Senior Note
Debt Instrument [Line Items]
Debt issuance date	May 15, 2015
Debt maturity date	Jun. 15, 2025
Long-term debt	$ 893.6	893.3
Long term debt instrument interest rate stated percentage	4.00%
Unamortized discount on senior notes	$ (6.4)	(6.7)
5.500% Senior Note
Debt Instrument [Line Items]
Debt issuance date	May 15, 2015
Debt maturity date	Jun. 15, 2045
Long-term debt	$ 345.5	345.5
Long term debt instrument interest rate stated percentage	5.50%
Unamortized discount on senior notes	$ (4.5)	(4.5)
4.125% Senior Note
Debt Instrument [Line Items]
Debt issuance date	Sep. 12, 2012
Debt maturity date	Sep. 12, 2022
Long-term debt	$ 348.5	348.4
Long term debt instrument interest rate stated percentage	4.125%
Unamortized discount on senior notes	$ (1.5)	(1.6)
5.800% Senior Note
Debt Instrument [Line Items]
Debt issuance date	Apr. 06, 2011
Debt maturity date	May 01, 2021
Long-term debt	$ 449.4	449.3
Long term debt instrument interest rate stated percentage	5.80%
Unamortized discount on senior notes	$ (0.6)	(0.7)
Line of Credit
Debt Instrument [Line Items]
Syndicated revolving credit facility	$ 440.0	$ 495.0