XML 77 R66.htm IDEA: XBRL DOCUMENT
v3.23.3

Derivatives - Undesignated Hedges (Parenthetical) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Cash Flow and Fair Value Hedges |  |  |  |
Foreign exchange losses on settlement assets and obligations, cash balances, and other assets and liabilities | $ 18.4 | $ 40.6 | $ 21.3 | $ 90.4

X
- References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsAndHedgesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents Foreign Exchange Gain Loss on Settlement Assets and Obligations, Other Assets and Other Liabilities and Cash Balances + References No definition available. + Details
Name: | wu_ForeignExchangeGainLossOnSettlementAssetsAndObligationsOtherAssetsAndOtherLiabilitiesAndCashBalances
Namespace Prefix: | wu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration