laravel pass data from controller to jquery using json

I want to pass data from controller to jquery using json don't know where is the problem but fro the jquery code I think its working fine as I tested the success code but can't get back the result from controller

home.blade

    <form role="form" name="form_address" id="form_address" action="" method="POST"  enctype="multipart/form-data">
     {{ csrf_field() }}
  <input type="text" id="postal_code" onFocus="geolocate()">
  <input type="text" id="totaldistance"  onFocus="geolocate()">
 </form>
  <button id="save_address">Save</button>

 <script>
$("#save_address").click(function (e) {
$.ajaxSetup({
    headers: {
         'X-CSRF-TOKEN': $('meta[name="_token"]').attr('content')
    }
   });

   e.preventDefault();
  var form = document.forms.namedItem("form_address");
  var formData = new FormData(form); 
  $.ajax({
     type: "get",
    url: 'Get_distance',
    contentType: false,
    data: formData, 
    processData: false,
    success: function(data) {
      $('#totaldistance').val(data.distance); 
    }
   });
  });

web.php

Route::post('Get_distance','HomeController@getdistance');

controller

public function getdistance(Request $request)
{
  $distance =$request->postal_code;

  return Response::json(array(
    'distance' => $distance,  
  ));
}