Revenues - Deferred Revenues and Remaining Performance Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Deferred revenue	$ 3.9	$ 6.2
Deferred revenue, revenue recognized	2.3
Deferred revenue balance from contracts with remaining performance obligations	$ 3.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligations due per period	19.00%
Expected timing of performance obligation satisfaction, period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligations due per period	38.00%