How to read JsonResponse in php

How to get id from here

JsonResponse {#457 ▼
  #data: "{"bill":{"id":11,"invoice_no":"9m36r9_1459170388239"}}"
  #callback: null
}

I am getting this output from this laravel code

return Response::json($response);

I tried json_decode but not worked here, a blank output is coming.

Thanks for any help.

via Chebli Mohamed