ng-show/ng-if doesn't update dom height immediately

I don't know Ionic well enough to say why it updates so slow, but you should be able to solve it either by activating native scrolling with the overflow-scroll attribute:

<ion-content ng-controller="controller" overflow-scroll="true">

Or by injecting $ionicScrollDelegate in your controller and calling resize manually:

$scope.toggle = function() {
  $scope.test.show_detail = !$scope.test.show_detail;
  $ionicScrollDelegate.resize();
};