Dispositions - Gain on Sale (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
	Mar. 17, 2020	Jun. 30, 2020	Jun. 30, 2020
Less carrying amount of assets and liabilities:
Net gain on sale, before taxes			$ 16.2
Geneva
Consideration received
Cash	$ 38.4	$ 38.4	38.4
Less carrying amount of assets and liabilities:
Intangible assets		17.9	17.9
Other assets		3.2	3.2
Other liabilities		(1.9)	(1.9)
Less: Goodwill allocation	23.5	23.5	23.5
Net gain on sale, before taxes	16.2		16.2
Geneva | Minimum
Consideration received
Contingent consideration	20.5	20.5	20.5
Geneva | Previously reported
Consideration received
Cash	38.6
Less carrying amount of assets and liabilities:
Intangible assets	17.9
Other assets	0.3
Less: Goodwill allocation	23.5
Net gain on sale, before taxes	17.4
Geneva | Previously reported | Minimum
Consideration received
Contingent consideration	$ 20.5
Geneva | Adjustments
Consideration received
Cash		(0.2)	(0.2)
Less carrying amount of assets and liabilities:
Other assets		2.9	2.9
Other liabilities		(1.9)	$ (1.9)
Net gain on sale, before taxes		$ (1.2)