Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 3.8	$ 4.2	$ 4.3
Charged to Expense	2.0	1.3	1.7
Deductions	(2.3)	(1.7)	(1.8)
Balance End of Year	3.5	3.8	4.2
Deferred income tax asset valuation allowance:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	1.1	1.3	1.2
Additions	0.0	0.1	0.1
Deductions	(0.6)	(0.3)	0.0
Balance End of Year	$ 0.5	$ 1.1	$ 1.3