Regex to grab ID from a Twitter post

/**
* Grab the status id from a twitter URL
*
*/
public function replyTweetId($url)
{
    $regex = '/https?:\/\/twitter.com\/[a-zA-Z_]{1,20}\/status\/([0-9]*)/';
    preg_match($regex, $url, $match);
    $id = $match[1];
    return $id;
}