Revenue - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	204 Months Ended
	May 31, 2019	Dec. 31, 2035	Sep. 30, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue transferred to buyer during sale	$ 22.0
Deferred Service Revenue			$ 9.4	$ 33.4
Minimum [Member] | Subsequent Event [Member] | Scenario, Forecast [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Recognition of Deferred Revenue, Expected Annual Amount		$ 0.1
Maximum [Member] | Subsequent Event [Member] | Scenario, Forecast [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Recognition of Deferred Revenue, Expected Annual Amount		$ 1.0