How To get transaction details in commerce checkout complete page
In general, for Drupal 7, you could do the following:

/**
 * Implements hook_form_FORM_ID_alter().
 */
function  MODULE_form_commerce_checkout_form_complete_alter(&amp;$form, &amp;$form_state, $form_id) {
  $order_id = $form_state['order']-&gt;order_id;
  // Use the entity field query to get transaction entities.
  $query-&gt;entityCondition('entity_type', 'commerce_payment_transaction')
    -&gt;propertyCondition('order_id', $order_id);
  $result = $query-&gt;execute();
  if (!empty($result) &amp;&amp; !empty($result['commerce_payment_transaction'])) {
    // Load the Payment Transactions
    $transactions = commerce_payment_transaction_load_multiple(array_keys($result['commerce_payment_transaction']));
    $form['payment_status']['#markup'] = '&lt;h2&gt;' . t('Payment Pending') . '&lt;/h2&gt;';
    foreach ($transactions as $transaction) {
      if ($transaction['status'] == "success") {
        $form['payment_status']['#markup'] = '&lt;h2&gt;' . t('Payment Received!') . '&lt;/h2&gt;';
        break;
      }
    }
  }
  else {
    $form['payment_status']['#markup'] = '&lt;h2&gt;' . t('Error. No Payment Transactions.') . '&lt;/h2&gt;';
  }
}