Revenue - Disaggregation of Revenue Earned from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue
Revenues from contracts with customers		$ 1,052.9	$ 1,035.0	$ 3,142.0	$ 3,219.1
Other revenues	[1]	44.9	54.6	162.7	164.5
Revenues		1,097.8	1,089.6	3,304.7	3,383.6
Consumer money transfers
Revenue
Revenues from contracts with customers		990.8	945.0	2,933.8	2,913.6
Other revenues	[1]	28.2	37.4	95.7	94.7
Revenues		1,019.0	982.4	3,029.5	3,008.3
Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]		26.0	13.0	111.7
Other revenues	[1],[2]		16.6	16.7	55.7
Revenues	[2]		42.6	29.7	167.4
Other services
Revenue
Revenues from contracts with customers		62.1	64.0	195.2	193.8
Other revenues	[1]	16.7	0.6	50.3	14.1
Revenues		78.8	64.6	245.5	207.9
North America
Revenue
Revenues from contracts with customers		403.3	416.0	1,190.1	1,285.7
North America | Consumer money transfers
Revenue
Revenues from contracts with customers		369.5	383.6	1,089.1	1,171.3
North America | Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]				17.9
North America | Other services
Revenue
Revenues from contracts with customers		33.8	32.4	101.0	96.5
Europe and CIS
Revenue
Revenues from contracts with customers		241.1	283.3	744.0	903.8
Europe and CIS | Consumer money transfers
Revenue
Revenues from contracts with customers		238.4	251.3	718.1	808.2
Europe and CIS | Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]		26.0	13.0	80.4
Europe and CIS | Other services
Revenue
Revenues from contracts with customers		2.7	6.0	12.9	15.2
Middle East, Africa, and South Asia
Revenue
Revenues from contracts with customers		224.5	156.7	658.8	478.5
Middle East, Africa, and South Asia | Consumer money transfers
Revenue
Revenues from contracts with customers		224.4	156.6	658.5	477.8
Middle East, Africa, and South Asia | Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]				0.4
Middle East, Africa, and South Asia | Other services
Revenue
Revenues from contracts with customers		0.1	0.1	0.3	0.3
Latin America and the Caribbean
Revenue
Revenues from contracts with customers		132.2	122.5	387.2	361.0
Latin America and the Caribbean | Consumer money transfers
Revenue
Revenues from contracts with customers		106.7	97.0	306.2	279.2
Latin America and the Caribbean | Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]				0.5
Latin America and the Caribbean | Other services
Revenue
Revenues from contracts with customers		25.5	25.5	81.0	81.3
East Asia and Oceania
Revenue
Revenues from contracts with customers		51.8	56.5	161.9	190.1
East Asia and Oceania | Consumer money transfers
Revenue
Revenues from contracts with customers		$ 51.8	$ 56.5	$ 161.9	177.1
East Asia and Oceania | Foreign exchange and payment services
Revenue
Revenues from contracts with customers	[2]				12.5
East Asia and Oceania | Other services
Revenue
Revenues from contracts with customers					$ 0.5

[1] Includes revenue from the sale of derivative financial instruments, investment income generated on settlement assets primarily related to money transfer and money order services, and other sources.

[2] On August 4, 2021, the Company entered into an agreement to sell its Business Solutions business to Goldfinch Partners LLC and The Baupost Group LLC. The first closing occurred on March 1, 2022, the second occurred on December 31, 2022, and the final closing occurred on July 1, 2023. See Note 4 for further information regarding this transaction.