one checked or multi checked in checkbox

I'm using check box in form. but when one check box is checked, show the detail div. and when multi check not show the div with jquery.

HTML code:

<input type="checkbox" name="cb1" id="cb1" />
<input type="checkbox" name="cb2" id="cb2" />
<input type="checkbox" name="cb3" id="cb3" />
<input type="checkbox" name="cb4" id="cb4" />
<div id="detail" style="display:none"></div>