PHP

how to store api response to avariable in phpp

$url = "https://geocoder.api.here.com/6.2/geocode.json?app_id=NT2iR8TD1kAeCxERIow8&app_code=-r9pZGDuz6G5NWToLaCSUQ&searchtext=3891 Delwood Drive, Powell, OH, United States";
$url = str_replace(" ","%20",$url);
$json = @file_get_contents($url);
$details = json_decode($json, TRUE);
print_r($details);