SPGridView Filter Menu width alteration

Hi All,

A little background. I have created a SPGridView to get data from a sharepoint list and show on the page. This works fine.

I want to increase the width of filter menu options using css:

.ms-core-menu-list, .ms-core-menu-link, .ms-core-menu-link {
        height: auto;
        width: 400px !important;

However I am not able to increase the parent DIV element :

DIV element CSS classes = '.ms-core-menu-box .ms-core-menu-hasIcons .ms-core-defaultFont .ms-shadow'

The DIV has style attr width set to 252px. I tried JQuery to reset this but to no avail.

<div class="ms-core-menu-box ms-core-menu-hasIcons ms-core-defaultFont ms-shadow" title="" dir="ltr" contenteditable="false" style="top: -161px; ; visibility: visible; left: -47px;width: 252px; height: 307px; overflow-y: scroll;" flipped="false">

Any help or pointers is appreciated.

Thanks in advance!

BR,

Santosh