- (void)setDetailItem:(id)newDetailItem {
    if (detailItem != newDetailItem) {
        [detailItem release];
        detailItem = [newDetailItem retain];

        // Update the view.
        navigationBar.topItem.title = [detailItem description];
    }

    if (popoverController != nil) {
        [popoverController dismissPopoverAnimated:YES];
    }
}