Hello.
You surely mean that you enabled "Export documents" setting under Web site -> Documents node, in Step 2 - Objects selection, in export process, am I right? According to log you provided it seems that documents have been exported, since there is following line within your log:
Exporting 'Documents' objects
Maybe the problem is somewhere else, than they are not included within your export package. What exactly do you mean by "website it doesn't show any documents," please? Do you mean they are missing even in document tree in CMSDesk, or they contain no context? Did you do export / import between the same version of Kentico
CMS? Thank you in advance for clarification.
Best Regards,
Radek Macalik