How to Get User Detail Programatically on ListItem Field

How to Get SPUser Detail Programatically on ListItem Field

 using (SPSite site = new SPSite("http://servername/"))
            {
                using (SPWeb web = site.OpenWeb())
                {
                    SPList List=web.Lists["Voucher"];
                   foreach(SPListItem ListItem in List.Items)
                   {
                       SPFieldUser ownerField =ListItem.Fields.GetField("ColumnName") as SPFieldUser;
                       SPFieldUserValue ownerValue = ownerField.GetFieldValue(ListItem[ownerField.Id].ToString()) as SPFieldUserValue;
                       SPUser owner = ownerValue.User;
                       string ownersEmail = owner.Email;
                       Console.WriteLine("user Name"+ListItem["ColumnName"].ToString());
                       Console.WriteLine("Users Email Id....."+ownersEmail.ToString());
                       Console.WriteLine("User Name .........." + owner.Name);
                       Console.WriteLine("User Id ............." + owner.ID);
                       Console.WriteLine("User Login........." + owner.LoginName);
                   
                       Console.Read();
                   }
                }
            }