Customer Liabilities - Schedule of Customer Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Accrued service costs, current	$ 33.3	$ 51.0
Collections payable to clients, current	5.4	9.1
Customer deposits, current	1.7	0.0
Refund liabilities, current	1.0	0.6
Deferred revenue (contract liabilities), current	6.7	5.1
Current portion of customer liabilities	48.1	65.8
Refund liabilities, non-current	0.0	0.4
Deferred revenue (contract liabilities), non-current	18.6	17.3
Non-current portion of customer liabilities	18.6	17.7
Total customer liabilities	$ 66.7	$ 83.5