Other Current Liabilities - Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Current Liabilities
Deferred revenue	$ 87.0	$ 75.5
Accrued compensation	105.4	83.8
Accrued warranty	20.6	18.7	$ 19.6	$ 21.6
Contingent consideration	6.5	13.5
Income taxes payable	28.1	11.3
Other taxes payable	16.7	12.4
Derivative liabilities	2.4	1.8
Other accrued expenses	55.3	52.5
Other current liabilities	$ 322.0	$ 269.5