Quarterly Results of Operations (Unaudited) (Restated Condensed Consolidated Balance Sheets with Adjustments) (Additional Information) (Details) - Restatement Impacts - USD ($) $ in Millions	3 Months Ended						12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Write-off of Assets
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in trade receivables	$ (1.6)	$ (1.3)	$ (1.6)	$ (0.4)	$ (0.4)	$ 0.2	$ (2.5)	$ (0.6)
Increase (decrease) in prepaids and other assets	(7.6)	(6.7)	(6.6)	(5.7)	(3.9)	2.6	(12.4)	(6.9)
Increase (decrease) in other current liabilities	2.1	1.4	1.4	1.0	1.3	2.6	0.9	0.6
Reversal of Revenue
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in trade receivables	(0.6)						(1.3)
Increase (decrease) in prepaids and other assets	0.1						0.2
Correction for the timing and recognition of customer price concessions
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in trade receivables							(1.6)
Increase (decrease) in other current liabilities	0.2	0.2	0.2	0.3	0.2	0.3		0.2
Tax adjustments related to adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in other current liabilities	(0.4)	(0.4)	(0.3)	0.1	0.2		(1.2)	(0.4)
Increase (decrease) in other current assets			(0.1)
Increase (decrease) in deferred income taxes	0.6	0.3	0.4	0.1	0.7	0.6	2.4	0.3
Increase (decrease) in other long-term liabilities	0.9	0.9	0.9	(0.2)	(0.2)	0.2	3.6	0.9
Correction of other immaterial errors
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in trade receivables		(1.1)	(1.1)					(1.9)
Increase (decrease) in prepaids and other assets							0.5
Increase (decrease) in other current liabilities		(1.4)	(1.4)		0.8	1.2		(2.0)
Increase (decrease) in accrued compensation	$ 0.4	$ 0.4	$ 0.4	$ 0.4	$ 0.3	$ 0.3	$ 0.7	$ 0.4