Settlement Assets and Obligations - Receivables from selling agents and Business Solutions customers (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Receivables
Receivables from agents and Business Solutions customers	$ 1,274.3
Summary of activity in allowance for credit losses
Allowance for credit losses, Ending Balance	40.7
Receivables from agents
Receivables
Receivables from agents and Business Solutions customers	1,171.7
Summary of activity in allowance for credit losses
Allowance for credit losses, Beginning Balance	20.4
Current period provision for expected credit losses	19.9
Write-offs charged against the allowance	(4.7)
Recoveries of amounts previously written off	1.2
Impacts of foreign currency exchange rates and other	(0.9)
Allowance for credit losses, Ending Balance	35.9
Receivables from Business Solutions customers
Receivables
Receivables from agents and Business Solutions customers	61.9
Summary of activity in allowance for credit losses
Allowance for credit losses, Beginning Balance	4.5
Current period provision for expected credit losses	1.4
Write-offs charged against the allowance	(1.7)
Impacts of foreign currency exchange rates and other	0.6
Allowance for credit losses, Ending Balance	$ 4.8