sticky.js

$(document).scroll(function() {
  $(".sticky").offset(function() {
    var documentHeight = $(document).height();
    console.log(documentHeight);
    $this = $(this);
    var scrollTop = $(window).scrollTop();
    var offsetTop = $this.data("offset-top");

    if (scrollTop < 0) {
      scrollTop = 0;
    }

    var newTop = offsetTop + scrollTop;
    if (newTop < offsetTop) {
      newTop = offsetTop;
    }

    // Prevents jitter at the bottom and document from
    // infinitely expanding.
    var maxTop = documentHeight - $this.height();
    if (newTop > maxTop) {
      newTop = maxTop
    }

    // Prevents a bit of jitter since the current offset can be
    // not precisely the initial offset. 338 Vs. 338.12931923
    var currentTop = $this.offset().top;
    if ( Math.abs(currentTop - newTop) >= 1 ) {
      return { top: newTop }
    } else {
      return {}
    }
  });
});

make sure you take console.log out - will break IE8 and lower