<?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/2025"
  xmlns:ffd="http://xbrl.sec.gov/ffd/2025"
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      xlink:href="https://xbrl.sec.gov/ffd/2025/ffd-2025.xsd"
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    <context id="c-1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001044777</identifier>
        </entity>
        <period>
            <startDate>2025-08-06</startDate>
            <endDate>2025-08-06</endDate>
        </period>
    </context>
    <context id="c-2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001044777</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
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        </entity>
        <period>
            <startDate>2025-08-06</startDate>
            <endDate>2025-08-06</endDate>
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    <unit id="shares">
        <measure>shares</measure>
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    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="number">
        <measure>pure</measure>
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    <dei:EntityCentralIndexKey contextRef="c-1" id="f-16">0001044777</dei:EntityCentralIndexKey>
    <ffd:FormTp contextRef="c-1" id="f-17">S-8</ffd:FormTp>
    <ffd:SubmissnTp contextRef="c-1" id="f-18">S-8</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="c-1" id="f-19">EX-FILING FEES</ffd:FeeExhibitTp>
    <ffd:AmtSctiesRegd contextRef="c-2" decimals="0" id="f-20" unitRef="shares">2000000</ffd:AmtSctiesRegd>
    <ffd:MaxOfferingPricPerScty contextRef="c-2" decimals="2" id="f-21" unitRef="usd">15.30</ffd:MaxOfferingPricPerScty>
    <ffd:MaxAggtOfferingPric contextRef="c-2" decimals="2" id="f-22" unitRef="usd">30600000</ffd:MaxAggtOfferingPric>
    <dei:EntityRegistrantName contextRef="c-1" id="f-1">OneSpan Inc.</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg contextRef="c-2" id="f-2">false</ffd:PrevslyPdFlg>
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    <ffd:FeesOthrRuleFlg contextRef="c-2" id="f-5">true</ffd:FeesOthrRuleFlg>
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    <ffd:FeeRate contextRef="c-2" decimals="8" id="f-9" unitRef="number">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt contextRef="c-2" decimals="2" id="f-10" unitRef="usd">4225.86</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="c-1" decimals="2" id="f-11" unitRef="usd">30600000</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="c-1" decimals="2" id="f-12" unitRef="usd">4225.86</ffd:TtlFeeAmt>
    <ffd:TtlOffsetAmt contextRef="c-1" decimals="2" id="f-13" unitRef="usd">0</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="c-1" decimals="2" id="f-14" unitRef="usd">4225.86</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="c-2" id="f-15">&lt;div style="padding-left:36pt;text-indent:-18pt"&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%"&gt;(1)&lt;/span&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%;padding-left:5.18pt"&gt;In accordance with Rule 416 under the Securities Act of 1933, as amended, this registration statement shall be deemed to cover any additional securities that may from time to time be offered or issued to prevent dilution resulting from stock splits, stock dividends or similar transactions. &lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;span&gt;&lt;br/&gt;&lt;/span&gt;&lt;/div&gt;&lt;div style="padding-left:36pt;text-indent:-18pt"&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%"&gt;(2)&lt;/span&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%;padding-left:5.18pt"&gt;Consists of 2,000,000 shares issuable under the Amended and Restated 2019 Omnibus Incentive Plan, as amended.  &lt;/span&gt;&lt;/div&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%"&gt;(3)&lt;/span&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%;padding-left:5.18pt"&gt;Estimated solely for the purpose of calculating the registration fee pursuant to Rules 457(c) and 457(h) of the Securities Act of 1933, as amended, and based upon the average of the high and low prices of the Registrant&#x2019;s Common Stock as reported on &lt;/span&gt;&lt;span style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',serif;font-size:11pt;font-weight:400;line-height:120%"&gt;the Nasdaq Capital Marke&lt;/span&gt;t on July 31, 2026.</ffd:OfferingNote>
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