Segment Information - Supplemental Geographic and Customer Solution Set Information (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
		Feb. 07, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenue	[1]	$ 178.7	$ 420.6	$ 398.9	$ 815.9	$ 573.0
Finance & Risk
Segment Reporting Information [Line Items]
Revenue		104.6	249.2	241.6	489.8	341.9
Sales & Marketing
Segment Reporting Information [Line Items]
Revenue		74.1	171.4	157.3	326.1	231.1
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue		148.2	354.3	360.9	695.8	542.1
Operating Segments | North America | Finance & Risk
Segment Reporting Information [Line Items]
Revenue		80.4	193.6	200.8	386.6	302.7
Operating Segments | North America | Sales & Marketing
Segment Reporting Information [Line Items]
Revenue		67.8	160.7	160.1	309.2	239.4
Operating Segments | International
Segment Reporting Information [Line Items]
Revenue		56.4	68.4	76.0	139.6	91.0
Operating Segments | International | Finance & Risk
Segment Reporting Information [Line Items]
Revenue		43.4	55.9	63.9	113.4	75.7
Operating Segments | International | Sales & Marketing
Segment Reporting Information [Line Items]
Revenue		13.0	12.5	12.1	26.2	15.3
Corporate and other
Segment Reporting Information [Line Items]
Revenue		(25.9)	(2.1)	(38.0)	(19.5)	(60.1)
Corporate and other | Finance & Risk
Segment Reporting Information [Line Items]
Revenue		(19.2)	(0.3)	(23.1)	(10.2)	(36.5)
Corporate and other | Sales & Marketing
Segment Reporting Information [Line Items]
Revenue		$ (6.7)	$ (1.8)	$ (14.9)	$ (9.3)	$ (23.6)

[1] See Note 1 "Basis of Presentation" for further discussion.