How to get the unparsed entity attribute's value from XSLT

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<!DOCTYPE document [
<!ELEMENT document (employee)*>
<!ELEMENT employee (lastname, firstname)>
<!ELEMENT lastname (#PCDATA)>
<!ELEMENT firstname (#PCDATA)>
<!NOTATION FOO SYSTEM 'text/xml'>
<!ENTITY ATTACHMENT SYSTEM 'attach.xml' NDATA FOO>
<!ATTLIST employee
       detail ENTITY #IMPLIED>
]>
<document>
    <employee detail="ATTACHMENT">
        <lastname>Bob</lastname>
        <firstname>Kevin</firstname>
    </employee>
</document>

<?xml version="1.0" encoding="UTF-8"?>

<name>Bob Kevin</name>

<?xml version="1.0"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml" indent="yes"/>

<xsl:template match="document">
<Document>
        <xsl:apply-templates select="employee"/>
</Document>
</xsl:template>

<xsl:template match="employee">
Employee is:  <xsl:value-of select="@detail"/>
</xsl:template>

</xsl:stylesheet>

java -jar xalan.jar -IN doc.xml -XSL doc.xsl -OUT docout.xml

<?xml version="1.0" encoding="UTF-8"?>
<Document>
Employee is:  ATTACHMENT
</Document>

<?xml version="1.0" encoding="UTF-8"?>
<Document>
Employee is:  <name>Bob Kevin</name>
</Document>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:output method="xml" indent="yes"/>

<xsl:template match="document">
<Document>
        <xsl:apply-templates select="employee"/>
</Document>
</xsl:template>

<xsl:template match="employee">
Employee is:  <xsl:value-of select=
"unparsed-text(unparsed-entity-uri(@detail))"/>
</xsl:template>

</xsl:stylesheet>

<?xml version="1.0"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml" indent="yes"/>

<xsl:template match="document">
<Document>
        <xsl:apply-templates select="employee"/>
</Document>
</xsl:template>

<xsl:template match="employee">
Employee is: <xsl:copy-of select="document(unparsed-entity-uri(@detail))"/>
</xsl:template>

</xsl:stylesheet>

<xsl:copy-of select="document(unparsed-entity-uri(@detail))"/>