SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for sales returns and doubtful accounts [Roll Forward]
Reserves related to non trade receivables	$ 0.4
Reserves related to notes receivable and tax refund receivables		$ 5.6
Allowance for doubtful accounts
Allowance for sales returns and doubtful accounts [Roll Forward]
Balance at Beginning of Period	10.0	7.2	$ 3.7
Charged to Expenses	1.3	3.6	6.7
Write-offs	(9.2)	(0.8)	(3.4)
Other	0.0	0.0	0.2
Balance at End of Period	2.1	10.0	7.2
Allowance for sales returns
Allowance for sales returns and doubtful accounts [Roll Forward]
Balance at Beginning of Period	1.6	3.5	7.8
Charged to Expenses	1.8	1.6	3.5
Write-offs	0.0	0.0	0.0
Other	(1.6)	(3.5)	(7.8)
Balance at End of Period	1.8	1.6	3.5
Allowance for inventory returns
Allowance for sales returns and doubtful accounts [Roll Forward]
Balance at Beginning of Period	(0.8)	(2.7)	(6.4)
Charged to Expenses	(0.9)	(0.8)	(2.7)
Write-offs	0.0	0.0	0.0
Other	0.8	2.7	6.4
Balance at End of Period	(0.9)	(0.8)	(2.7)
Allowance for deferred tax assets
Allowance for sales returns and doubtful accounts [Roll Forward]
Balance at Beginning of Period	69.7	64.0	35.8
Charged to Expenses	(28.6)	6.0	28.6
Write-offs	(3.0)	(1.9)	0.0
Other	(19.2)	1.6	(0.4)
Balance at End of Period	$ 18.9	$ 69.7	$ 64.0