Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets:
Derivatives	$ 5.2	$ 7.2
Liabilities:
Derivatives	5.5	5.0
Fair Value, Measurements, Recurring
Assets:
Investments	13.1	11.9
Derivatives	5.2	7.2
Total assets	18.3	19.1
Liabilities:
Derivatives	5.5	5.0
Contingent Consideration	0.0	0.8
Total liabilities	5.5	5.8
Fair Value, Measurements, Recurring | Level 1
Assets:
Investments	13.1	11.9
Derivatives	0.0	0.0
Total assets	13.1	11.9
Liabilities:
Derivatives	0.0	0.0
Contingent Consideration	0.0	0.0
Total liabilities	0.0	0.0
Fair Value, Measurements, Recurring | Level 2
Assets:
Investments	0.0	0.0
Derivatives	5.2	7.2
Total assets	5.2	7.2
Liabilities:
Derivatives	5.5	5.0
Contingent Consideration	0.0	0.0
Total liabilities	5.5	5.0
Fair Value, Measurements, Recurring | Level 3
Assets:
Investments	0.0	0.0
Derivatives	0.0	0.0
Total assets	0.0	0.0
Liabilities:
Derivatives	0.0	0.0
Contingent Consideration	0.0	0.8
Total liabilities	$ 0.0	$ 0.8