How to make an inline-block element fill the remainder of the line?

.lineContainer {
    overflow: hidden; /* clear the float */
    border: 1px solid #000
}
.lineContainer div {
    height: 20px
} 
.left {
    width: 100px;
    float: left;
    border-right: 1px solid #000
}
.right {
    overflow: hidden;
    background: #ccc
}

<div class="lineContainer">
    <div class="left">left</div>
    <div class="right">right</div>
</div>