moving sidebar from left to right

The site is https://www.lancasterchildren.org/wordpress and I’m trying to move the sidebar to the right side of the post body. I tried change the float on the #content and #sidebar but It didn’t work. I also tried to take out the “position” line. but that didn’t do anything either. heres the css. thanx for any help!

#content {
background:#d6d3bf;
width:500px;
float:right;
position:relative;
border-left:1px dotted #000000;
margin:20px 0;
padding:0 25px 15px;
}

#sidebar {
color:#000;
width:240px;
float:left;
margin-top:0px;
margin-bottom:20px;
text-align:left;
padding:30px;
}