Income Taxes - U.S. and Foreign Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income from continuing operations before income taxes:
U.S.	$ 53.6	$ 68.3	$ 62.2
Foreign	38.1	34.7	27.7
Income from continuing operations before income taxes	91.7	103.0	89.9
Current:
Federal	4.7	7.1	12.7
State	0.5	(0.5)	1.3
Foreign	6.4	5.9	5.1
Total current tax provision	11.6	12.5	19.1
Deferred:
Federal	(1.8)	14.8	7.7
State	(0.1)	1.8	2.3
Foreign	1.7	0.5	0.3
Total deferred tax provision	(0.2)	17.1	10.3
Total provision for income taxes	$ 11.4	$ 29.6	$ 29.4