Restructuring and other (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 13, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and other		$ 67.0	$ 28.0	$ 253.0
Shuffle Tech Matter
Restructuring Cost and Reserve [Line Items]
Payments for Legal Settlements	$ 152.0
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other		41.0	9.0	37.0
Employee severance | contingencies related to COVID19
Restructuring Cost and Reserve [Line Items]
Restructuring and other		32.0
Acquisition-related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other		0.0	0.0	8.0
Acquisition-related costs | NYX
Restructuring Cost and Reserve [Line Items]
Restructuring and other				8.0
Contingent acquisition consideration
Restructuring Cost and Reserve [Line Items]
Restructuring and other		0.0	2.0	29.0
Legal and related
Restructuring Cost and Reserve [Line Items]
Restructuring and other		0.0	0.0	152.0
Restructuring, integration and other
Restructuring Cost and Reserve [Line Items]
Restructuring and other		$ 26.0	$ 17.0	$ 27.0