My parent div has a min-height of 100%.  An inner div with a position absolute has a min-height of 100%. When more content is added to the inner height, the parent height does not change?

The child element is no longer relative to the parent element since it is no longer part of the document flow. When you declare absolute positioning for an element, this is what happens. The element in question is removed from the document flow, or the structure of the html, even though the DOM itself remains unaltered. It becomes relative to the window if no parent element higher up in the document model has been explicitly declared as relative.It's as though the child element has been removed from the parent element, leaving it empty. When the height or width of the child element increases, it doesn't affect the height or width of the parent element, and the flow of preceding and following elements remains unchanged.The child element becomes a ghost that can pass through the box model of the parent element, without affecting its proportions. You can constrain the absolute positioned child by explicitly declaring relative positioning to a parent element - this way, the absolute positioned child won't pass the parent element's dimensions, this is particularly useful for aligning elements declared with absolute positioning.