This code snippet would be helpful to popup hover in Visualforce just like in Standard Detail Page as shown in Sample Output

Sample Output

Note: Works for both Standard and Custom Objects, record.Id should be Id of Standard/Custom object.

Visualforce Page

....
your code goes here
....
<a href="#" onmouseout="LookupHoverDetail.getHover('{!record.Id}').hide();" onmouseover="LookupHoverDetail.getHover('{!record.Id}', '/{!record.Id}/m?retURL=%2F{!record.Id}&isAjaxRequest=1').show();">{!record.Name}</a>
....
your code goes here
....

NOTE: For this post Mentioned only <a> tag once can embed this in various tags lik <apex:repeat>, <apex:pageBlockSection> etc.,

Happy coding! comment below if you need any help