Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue recognized from changes in transaction prices	$ 1.4	$ 0.4
Revenue recognized for services performed in periods prior to execution of new agreements	$ 4.0	0.2
Revenue performance obligation, period	PAS performance obligations are typically short in duration (often less than 1 day) with any uncertainty related to the associated variable consideration resolved as each increment of service (completion of a level of care review or an appeal) is completed which reflects the value the customer receives from the Company’s fulfillment of the performance obligation.
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 69.7	51.8
Revenue recognized, advanced billings	$ 66.7	$ 47.8