Position relative and Height on content

HTML

<div class="outer">
    <div class="inner"></div>    
</div>

CSS

.outer {
    position: relative;
    overflow: scroll;    
    border : 1px solid red;
    height: auto;
}
.inner {
    position: absolute;
    width: 1200px;
    height: 895px;  
    border : 1px solid yellow;
}