How can I confirm if text is outline?

When converting an InDesign, CS6, file to PDF/X-1a, and forcing the text to be converted to outline text . . .

• InDesign
  • Edit > Transparency Flattener Presets > New "Convert All Text to Outlines"
    • High Resolution
    • Convert All Text to Outlines
• PDF/X-1a
  • Advanced
  • Transparency Flattener
    • "Convert All Text to Outlines"
• Each PDF page has a small bit of transparency over text that must be flattened

. . . In the PDF (in Acrobat Pro 11), how can I tell if the text has actually been converted to outline?

The text remains editable; it is listed as text (by name etc.), I cannot find a relevant preflight that would confirm that the text has been converted to outline . . . which is not to say it isn't there.

Walton