Revenue Recognition (Extended Warranties and Post-Contract Support) (Details) - Extended warranties and post contract support - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Post-contract support contract, term		12 months
Deferred revenue	$ 37.8	$ 37.8	$ 40.7
Deferred revenue recognized	2.8	18.5
Estimation of future revenues	$ 24.3	$ 24.3
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Extended product warranty, term		1 year
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Extended product warranty, term		5 years