<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xml:lang="en-US"
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2021"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="exfy-20220613.xsd" xlink:type="simple"/>
    <context id="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001476840</identifier>
        </entity>
        <period>
            <startDate>2022-06-13</startDate>
            <endDate>2022-06-13</endDate>
        </period>
    </context>
    <dei:EntityCentralIndexKey
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV80L2ZyYWc6ZjE2Y2Q2NWQwZjEzNGYzZGIxN2Y2N2QzZTc2NzQ4ZTIvdGFibGU6ODI4YjIxMjkzYjcyNDhjY2ExZTBkYzc5MWNkNGNlMjQvdGFibGVyYW5nZTo4MjhiMjEyOTNiNzI0OGNjYTFlMGRjNzkxY2Q0Y2UyNF8wLTEtMS0xLTE2Njc5OA_5902ed44-7d3a-4d55-ab5b-316275e718b7">0001476840</dei:EntityCentralIndexKey>
    <dei:AmendmentFlag
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV80L2ZyYWc6ZjE2Y2Q2NWQwZjEzNGYzZGIxN2Y2N2QzZTc2NzQ4ZTIvdGFibGU6ODI4YjIxMjkzYjcyNDhjY2ExZTBkYzc5MWNkNGNlMjQvdGFibGVyYW5nZTo4MjhiMjEyOTNiNzI0OGNjYTFlMGRjNzkxY2Q0Y2UyNF8xLTEtMS0xLTE2Njc5OA_5877a74b-2390-4af5-b6e7-3afc1b8e3b11">false</dei:AmendmentFlag>
    <dei:DocumentType
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzE5_19283160-03a6-4593-a2fd-14cd3b5ff921">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8yMjc_5c4fcd6c-d6a3-484e-9fae-0e6a1fd00e3b">2022-06-13</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI0_edca4b01-84b1-4f3d-b7bf-c4bfedb0faa2">Expensify, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MzczZTUyNmM2ZDc5NGRlY2FjMDlhMmI0ODYzOThhYmQvdGFibGVyYW5nZTozNzNlNTI2YzZkNzk0ZGVjYWMwOWEyYjQ4NjM5OGFiZF8xLTAtMS0xLTE2Njc5OA_642491c6-ddf6-423a-847e-77b18a9826d2">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MzczZTUyNmM2ZDc5NGRlY2FjMDlhMmI0ODYzOThhYmQvdGFibGVyYW5nZTozNzNlNTI2YzZkNzk0ZGVjYWMwOWEyYjQ4NjM5OGFiZF8xLTItMS0xLTE2Njc5OA_aa844378-5f8e-44ca-8a17-978afbefd967">001-41043</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MzczZTUyNmM2ZDc5NGRlY2FjMDlhMmI0ODYzOThhYmQvdGFibGVyYW5nZTozNzNlNTI2YzZkNzk0ZGVjYWMwOWEyYjQ4NjM5OGFiZF8xLTQtMS0xLTE2Njc5OA_7d93bde6-e45f-4753-b9d1-f08fc06e74ec">27-0239450</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI1_7425e643-0e01-482c-810f-3ac3fcd044fb">401 SW 5th Ave</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzIx_af540dec-8ffd-4e63-9c88-dd6b1e1747f2">Portland</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI2_9c527ea4-14b1-43be-9f9c-f81e9c55d5f1">OR</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI3_172ac4bc-0c00-440d-a105-b6fda552b2f3">97204</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI4_ccaed612-302b-4846-a0ef-8ced3f16179a">971</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzIy_36549200-08cb-47f1-94d0-223cc40e92ac">365-3939</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6YmQ3OWJhYjhkNTQzNGQwYTk2YTBjZjkzNTVkMGRlYzcvdGFibGVyYW5nZTpiZDc5YmFiOGQ1NDM0ZDBhOTZhMGNmOTM1NWQwZGVjN18wLTAtMS0xLTE2Njc5OA_d022412a-5780-4423-912b-e659c036a3e4">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6YmQ3OWJhYjhkNTQzNGQwYTk2YTBjZjkzNTVkMGRlYzcvdGFibGVyYW5nZTpiZDc5YmFiOGQ1NDM0ZDBhOTZhMGNmOTM1NWQwZGVjN18yLTAtMS0xLTE2Njc5OA_7de3bc46-fbad-4336-8515-3c053d4c1ed2">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6YmQ3OWJhYjhkNTQzNGQwYTk2YTBjZjkzNTVkMGRlYzcvdGFibGVyYW5nZTpiZDc5YmFiOGQ1NDM0ZDBhOTZhMGNmOTM1NWQwZGVjN180LTAtMS0xLTE2Njc5OA_e16848a2-a4f0-42ea-97fc-93c1e779df8e">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6YmQ3OWJhYjhkNTQzNGQwYTk2YTBjZjkzNTVkMGRlYzcvdGFibGVyYW5nZTpiZDc5YmFiOGQ1NDM0ZDBhOTZhMGNmOTM1NWQwZGVjN182LTAtMS0xLTE2Njc5OA_547a2140-58c1-479b-ba4a-2149b522dd1a">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MDdjM2MwNTAyMzQyNDA0NDk3YWMxZmY3ZTZmMjFhNjkvdGFibGVyYW5nZTowN2MzYzA1MDIzNDI0MDQ0OTdhYzFmZjdlNmYyMWE2OV8xLTAtMS0xLTE2Njc5OA_20640d4e-28e0-4a6d-9968-1229e11f1300">Class A Common Stock, par value $0.0001 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MDdjM2MwNTAyMzQyNDA0NDk3YWMxZmY3ZTZmMjFhNjkvdGFibGVyYW5nZTowN2MzYzA1MDIzNDI0MDQ0OTdhYzFmZjdlNmYyMWE2OV8xLTItMS0xLTE2Njc5OA_1ffc6fda-36b6-4d0a-a58e-90818a151763">EXFY</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGFibGU6MDdjM2MwNTAyMzQyNDA0NDk3YWMxZmY3ZTZmMjFhNjkvdGFibGVyYW5nZTowN2MzYzA1MDIzNDI0MDQ0OTdhYzFmZjdlNmYyMWE2OV8xLTQtMS0xLTE2Njc5OA_8b9edf4d-bde4-4b4c-9c33-b6f828751f38">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzIz_eb02c844-a00d-4d19-bfa0-0193b34d3100">true</dei:EntityEmergingGrowthCompany>
    <dei:EntityExTransitionPeriod
      contextRef="i254c1bbb2f2e4c93b89491db058d9a42_D20220613-20220613"
      id="id3VybDovL2RvY3MudjEvZG9jOjFkZTNkYTRkMjY2ZTQzZDdhY2E5ZTZhNjkxYzIzYmZlL3NlYzoxZGUzZGE0ZDI2NmU0M2Q3YWNhOWU2YTY5MWMyM2JmZV8xL2ZyYWc6YWVlMjE4N2Y5NDExNGM4Yzg0YmRlNzE0YjA1ZjUwMWYvdGV4dHJlZ2lvbjphZWUyMTg3Zjk0MTE0YzhjODRiZGU3MTRiMDVmNTAxZl8xMzI5_b2e65e8d-178f-48aa-855e-2dbab696c990">false</dei:EntityExTransitionPeriod>
</xbrl>
