Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Deferred revenues	$ 14.8	$ 26.7
Net operating loss carryovers	0.7	1.3
Equity-based compensation	9.2	3.9
Other	10.7	8.9
Total deferred tax assets	35.4	40.8
Deferred tax liabilities:
Goodwill and other intangibles	(178.9)	(193.8)
Property, equipment and computer software	(41.9)	(36.2)
Property, equipment and computer software	(28.0)	(26.1)
Other	(7.5)	(9.3)
Total deferred tax liabilities	(256.3)	(265.4)
Net deferred tax liability	$ (220.9)	$ (224.6)