Revenue Recognition, Contracts with Customers - Revenue Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Total revenue, expected to be recognized	$ 13.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue from Contract with Customer [Abstract]
Total revenue, expected to be recognized	$ 5.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue from Contract with Customer [Abstract]
Total revenue, expected to be recognized	$ 8.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period