public function getFactsWithoutNils()
	{
		if ( $this->nonNilsFactsCache )
		{
			return $this->nonNilsFactsCache;
		}
		else
		{
			$nonNilsFactsCacheExpression = "xfi:non-nil-facts-in-instance(/xbrli:xbrl)";
			if ( ! is_null( $this->groupFilterExpression ) )
			{
				$nonNilsFactsCacheExpression .= "[{$this->groupFilterExpression}]";
			}

			// Because this is the first time the facts have been accessed there are only parameters to be used as variables
			$this->nonNilsFactsCache = BufferedNodeIterator::fromSourceWithClone( $this->evaluateXPath( $this, $nonNilsFactsCacheExpression, $this->parameters ), false );
			// $this->nonNilsFactsCache = $this->evaluateXPath( $this, $nonNilsFactsCacheExpression, $this->parameters );
			return $this->nonNilsFactsCache; //->CloneInstance();
		}
	}