Get Top Parent category id from sub-child category in magento

// Get Parent Category Id

<?php

$_cat = new Mage_Catalog_Block_Navigation();

$curent_cat = $_cat->getCurrentCategory();

$curent_cat_id = $curent_cat->getId();?>

<?php $parentId=Mage::getModel('catalog/category')->load($curent_cat_id)->getParentId();

echo $parentId; // $parentId will print your current category's parent Id

?>

   // Get Top Parent Category Id

    $_cat = new Mage_Catalog_Block_Navigation();

    $curent_cat = $_cat->getCurrentCategory();  // Get Current Category

    $category_ids = $_cat->getCurrentCategory()->getParentCategory()->getPath(); 
    // Get Parent Category detail

    $cat_id = explode('/',$category_ids);   

    $top_parent_id = $cat_id[2];     // Get Parent Category Id

    echo  $top_parent_id; // $top_parent_id will print your current category's top parent Id.

   Suppose you click on Submenu 2.2.3 page and you want to find Top parent category id (Get Category Id)