Today I read in a xbrl instance from the SEC just to see how the reference, labels and calculations are implemented in Gepsio.
But i ran into an error trying to read in this instance > http://www.sec.gov/Archives/edgar/data/1001250/000110465911005139/0001104659-11-005139-xbrl.zip
I narrowed the error down to this
after the line CalculationArc ContributingConceptCalculationArc = CurrentCalculationLink.GetCalculationAr(CurrentLocator);
if this returns a null (not finding the calculationarc by id)
it will give an exception a few lines further into the procedure on this line
if (ContributingConceptCalculationArc.Weight != (decimal)(1.0))