EDIT : A better approach here:
How to create a custom modal popup – and how to close it clicking outside of it
$( "#idSelect" ).click(function( e ) {
e.stopPropagation();
$("#idDiv").toggle();
});
$( "#idDiv" ).on('click',function( e ) {
e.stopPropagation();
});
$( document ).on('click', function( e ) {
if( e.target.id != 'idDiv' ){
$( "#idDiv" ).hide();
}
});