<%= form_for @application_detail, :html => {:class => "form-horizontal"} do |f| %>
  <% if @application_detail.errors.any? %>  
    <div id="error_explanation" class="alert alert-error">  
      <h2><%= pluralize(@application_detail.errors.count, "error") %> prohibited this record from being saved:</h2>  
      <ul>  
      <% @application_detail.errors.full_messages.each do |msg| %>  
        <li><%= msg %></li>  
      <% end %>  
      </ul>  
    </div>  
  <% end %>
  <div class="well">
    <%= @application_detail.description.html_safe %>
  </div>
  <div class="control-group">
    <%= f.label :the_text, :class => "control-label" %>
    <div class="controls">
    <%= f.text_area :the_text, :rows => 3 %>
    </div>
  </div>
  <p>
    <button class="btn" type="submit">Save changes</button>
  </p>
<% end %>

<%= form_for @application_detail, :html => {:class => "form-horizontal"} do |f| %>
  <% if @application_detail.errors.any? %>
    <div id="error_explanation" class="alert alert-error">
      <h2><%= pluralize(@application_detail.errors.count, "error") %> prohibited this record from being saved:</h2>
      <ul>
      <% @application_detail.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>
  <div class="well">
    <%= @application_detail.description.html_safe %>
  </div>
  <div class="form-group">
    <%= f.label :the_text, class: 'control-label col-md-3' %>
    <div class="col-md-6">
      <%= f.text_area :the_text, rows: 3, class: 'form-control' %>
    </div>
  </div>
  <p>
    <button class="btn btn-primary" type="submit">Save changes</button>
  </p>
<% end %>

Update the application details form for Bootstrap 3
Update the application details form for Bootstrap 3
