When your links are extending outside the width of your block level element’s even with an overflow property just apply these rules:
white-space: pre; /* CSS 2.0 */ white-space: pre-wrap; /* CSS 2.1 */ white-space: pre-line; /* CSS 3.0 */ white-space: -pre-wrap; /* Opera 4-6 */ white-space: -o-pre-wrap; /* Opera 7 */ white-space: -moz-pre-wrap; /* Mozilla */ white-space: -hp-pre-wrap; /* HP Printers */ word-wrap: break-word; /* IE 5+ */
Source: http://perishablepress.com/press/2010/06/01/wrapping-content/