Acquisitions - Other Acquisitions (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Asset Acquisition [Line Items]
Goodwill		$ 0.2
Deferred revenue		1.0
Sunset Assets
Schedule Of Asset Acquisition [Line Items]
Gain (loss) on disposition of assets		2.0
Deferred commission costs		2.2
Customer relationships
Schedule Of Asset Acquisition [Line Items]
Intangible assets		1.1
Third-Party Payor | Customer relationships
Schedule Of Asset Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 0.2	$ 1.6