SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts
Valuation and Qualifying Accounts
Balance at beginning of period	$ 23.6	$ 25.6	$ 20.2
Charged to cost and expenses	1.8	6.0	3.7
Additions (Deductions)	(2.4)	(8.0)	1.7
Balance at end of period	23.0	23.6	25.6
Valuation allowance on deferred tax assets
Valuation and Qualifying Accounts
Balance at beginning of period	37.2	18.5	15.5
Charged to cost and expenses	2.5	4.8	3.0
Additions (Deductions)	(0.1)	13.9
Balance at end of period	$ 39.6	$ 37.2	$ 18.5