Document CALs are allocated per User/Document combination. 14 users can each have three document cals.
And you should take into account that Document CALs may be allocated, but that doesn't mean they are in use already. It means that they are reserved for possible use by users visiting this particular document, and cannot be allocated to any other document. In your example, you have:
50 Document CALS in license
35 Document CALs allocated (reserved) to documents
14 Document CALs assigned (in use) from this pool of 35.
Have a look at this tool: QlikView Server CAL Manager. Search for it in the forum, download it and set it up in your system. It wiull help you in your actual issue and in many others you may face in the future regarding license management.