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
Changes in valuation and qualifying accounts
Balance at Beginning of Year	$ 0.9	$ 1.0	$ 0.7
Additions Charged to Costs and Expenses	0.5	0.7	0.7
Reductions	(1.0)	(0.8)	(0.5)
Balance at End of Year	0.4	0.9	1.0
Tax valuation account
Changes in valuation and qualifying accounts
Balance at Beginning of Year	6.8	12.3	21.3
Additions Charged to Costs and Expenses	0.0	0.0	0.0
Reductions	(0.2)	(5.5)	(9.0)
Balance at End of Year	$ 6.6	$ 6.8	$ 12.3