In my company, almost all the processes are described
All could be divided into several groups.

1. ISO
Manual ISO provides a general work flow and have the least detail as possible.
No one would be able to learn about the process , if it were written down exactly.
The company is audited every year of compliance with these procedures . If the process would be more accurately described, the harder it was to us to pass the audit :)

2. More detailed procedures.
Several stages of the process, is described very accurately.
"Manual handling of incoming documents"
This is described by the points what user should do with documents, but without details.: "...move files to INCOMING folder" ther is now explementation, how to move files to other folder :)

3. Instruction "how to"
For some FAQ we prepare wery detailed instructions (with arrows, and print screen). For example: "How to purge drawing's", "how, to publish drawings to pdf"

4. CAD Standard.

5. Maintance and administration manuals
This is not for end user. This is for administrators and for "internal security" If i'm on vacation (or I decide do change my work :) ), someone needs to know as it all works.
Of course this help me too. If I need to set something once a year is more than likely that I forget how I set this before :)

Not explain anything in the instruction. In CAD Standard is a few sentences, why wy have CAD standard. But I put it there to make it look nice :)
I am sure that few people read it :)
I try to explain "why", during training course.

Currently, we have all the documents pdf.

In my opinion, ther is nothing bad having procedures and manuals for everything.
Of course ther is lot of work with keeping everything updated.

More "intelligent" supervisor and employees, less precise instructions. :D