Revenue Recognition Estimated Revenue Expected to be Recognized In the future (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)
Revenue Recognition [Abstract]
Revenue expected to be recognized on VCP contracts sold as of period end	$ 89.6
Vehicle maintenance program, contract term	5 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue Recognition [Abstract]
Revenue expected to be recognized on VCP contracts sold as of period end	$ 29.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue Recognition [Abstract]
Revenue expected to be recognized on VCP contracts sold as of period end	$ 44.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue Recognition [Abstract]
Revenue expected to be recognized on VCP contracts sold as of period end	$ 15.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years