Navigation Drop-down menu is inheriting the width of its parent and cropping its children if they were long

I have created my main navigation using CSS display: table as it shown below:

The with of the dropdown menus are not exceeding the width of the parent, which means if there was a long text inside the drop-down menu, it will be cropped as the image below demonstrate:

How can I make my dropdown menus adapt to the width of their children and not to the width of its parent just like shown in the image below:

So the drop-down menus will stretch to fit the width of there parent and if any of their children is longer than that width, their width should increase to adapt.

HTML:

<nav class="mainMenu">
    <ul>
        <li> <a <?php href( 'index.php');?>>Index</a>
        </li>
        <li> <a <?php href( 'modules.php');?>>Modules</a>
        </li>
        <li class="subMenu"> <a <?php href( 'page.php');?>>Dropdown</a>

            <ul>
                <li> <a <?php href( '');?>>Short Text</a>
                </li>
                <li> <a <?php href( '');?>>Dropdown Longer Text</a>
                </li>
            </ul>
        </li>
        <li class="subMenu"> <a <?php href( 'page.php');?>>Dropdown</a>

            <ul>
                <li> <a <?php href( '');?>>Sub menu item which is longer than its parent</a>
                </li>
                <li> <a <?php href( '');?>>Short Text</a>
                </li>
            </ul>
        </li>
    </ul>
</nav>

CSS:

/*Header*/
 #header {
    background-color: #fff;
    width: 100%;
    display: inline-block;
    position: relative;
    z-index: 10000;
}
/*Header > Content Container*/
 #header .content {
    width: 1024px;
    padding: 0 20px;
    margin: 0 auto;
    position: relative;
}
/*Header > Main Menu*/
 #header .mainMenu {
    display: table;
    float: right;
}
#header .mainMenu ul {
    display: table-row;
    position: relative;
}
#header .mainMenu ul li {
    display: table-cell;
    position: relative;
}
/*Header > Main Menu > Menu Links*/
 #header .mainMenu ul li a {
    padding: 10px 15px;
}
#header .mainMenu ul li a:hover {
    color: #2B508F;
}
#header .mainMenu ul li a.active, #header .mainMenu ul li a.active:hover {
    color: #fff;
    background-color: #2B508F;
    cursor: default !important;
}
/*Header > Main Menu > Dropdown Menus*/
 #header .mainMenu ul ul {
    background-color: #fff;
    padding: 1px;
    min-width: 100%;
    position: absolute;
    top: 100%;
    left: 0;
    text-align: left;
    overflow: hidden;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    -webkit-transition: all .1s linear;
    -moz-transition: all .1s linear;
    -ms-transition: all .1s linear;
    -o-transition: all .1s linear;
    transition: all .1s linear;
}
#header .mainMenu ul li:hover > ul {
    pointer-events: auto;
    visibility: visible;
    opacity: 1;
}
#header .mainMenu ul ul li {
    width: 100%;
    display: block;
}
/*Header > Main Menu > Dropdown Menu Links*/
 #header .mainMenu ul ul li a {
    display: block;
}
#header .mainMenu ul ul li a:hover {
}
#header .mainMenu ul ul li a.active, #header .mainMenu ul ul li a.active:hover {
}
/*Header > Main Menu > Dropdown Menu Parent Link*/
 #header .mainMenu .subMenu:hover > a {
    color: #2B508F;
}
#header .mainMenu .subMenu:hover > a.active {
    color: #2B508F;
}

JSFiddle: http://ift.tt/1HjLuJf