XML 119 R100.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Derivatives - Undesignated Hedges (Parenthetical) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Cash Flow and Fair Value Hedges |  |  |
Foreign exchange gains/(losses) on settlement assets and obligations, cash balances, and other assets and liabilities | $ (56.1) | $ (37.0) | $ (33.1)

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