Divestitures and Business Combinations - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jan. 07, 2019
Discontinued Operations, Disposed of by Sale \| MyCase
Business Acquisition [Line Items]
Consideration for disposal of subsidiary	$ 193.0
Proceeds from divestiture of subsidiary	192.2
Employee retention bonus pool	2.2
Cash divested	0.8
Working capital adjustment	$ 0.6
Retention period	1 year
Gain on sale of subsidiary	$ 187.6
Assets divested	4.6
Capitalized software divested	3.9
Deferred revenue divested	2.8
Goodwill divested	$ 2.3
Dynasty
Business Acquisition [Line Items]
Percentage of voting equity interest		100.00%
Consideration transferred		$ 60.2
Amount held for adjustments		6.0
Transaction costs		$ 0.3

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