Yes, it can be done, but you need OCR (Optical Character Recognition) software. (You may already have this software. It usually comes on the CD that you get when you buy your scanner.)
The difficulty you may have is that OCR software tends to read .tif file format, and I'm betting that you didn't save your 'documents' using .tif.
Presumably, you still have the original paper document.
Might I suggest that you download and install Softi FreeOCR? As it's name suggests, it's a FREE programme. It's not exactly top of the image recognition stakes, but it does the job. Unfortunately, you will lose any formatting, and any fonts that you have stipulated in the original document, so you will need to edit the end result.
As the other respondent says, you may be better off retyping the document but, if it's a lengthy document, it may just be worth your while to have a go with this OCR software.
Best of luck to you.