<h:form id="main">
        <p:commandButton value="Basic" id="createDialog" action="#{testView.action}" update=":window:panel" oncomplete="PF('dlg1').show();"/>
</h:form>

<h:form id="window">
    <p:dialog modal="true" header="Basic Dialog" widgetVar="dlg1" >
       <p:panel id="panel">
            <p:editor id="editor" widgetVar="editorWidget" value="#{testView.input}" />
        </p:panel>
    </p:dialog>
</h:form>

.ui-overlay-visible .ui-editor iframe {
display: inline !important;
}