Noncontrolling Interests (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Noncontrolling interests
Balance at beginning of period	$ 8.8	$ 6.9	$ 8.1	$ 6.7
Net income	0.3	0.6	0.7	0.7
Foreign currency translation adjustments	(0.4)	0.4	(0.3)	0.5
Balance at end of period	$ 8.7	7.4	8.7	7.4
ASU No. 2014-09
Noncontrolling interests
Impact of ASC 606 adoption		$ (0.5)	$ 0.2	$ (0.5)