The reason I asked about bindcomplete is it looks like that event needs to be called to build the child grid. Here is my code for this:
$("#SummaryGrid").bind('bindingcomplete', function (event) {
if (event.target.id == "SummaryGrid") {
$("#SummaryGrid").jqxGrid('beginupdate');
var datainformation = $("#SummaryGrid").jqxGrid('getdatainformation');
for (i = 0; i < datainformation.rowscount; i++) {
$("#SummaryGrid").jqxGrid('setrowdetails', i, "<div id='grid" + i + "' style='margin: 10px;'></div>", 220, true);
}
$("#SummaryGrid").jqxGrid('resumeupdate');
}
});