There are several ways that employees create value at a company;
- Through the work employees complete and the adherence to processes they follow.
- and (perhaps equally important) is the work they complete to create, modify, or remove processes.
These can be performed in.. MANY.. different ways; part of this comes existing and retained knowledge, some from documentation; part from communication; part from the actual methods and solutions used to solve problems.
At a high level; I've always approached the problem like this:
"If I get hit by a bus tomorrow morning; what will my employer lose?"
I personally strive for the answer to that question to always remain: "nothing". 
This does not mean that I strive to DO nothing; but rather that I strive to ensure that if I get hit by a bus and killed, that the company can work around my loss and continue on. To be able to achieve this; it's critical that any process I put in place be understood by the remaining employees well enough to proceed and be modified as needed to continue to serve the company's needs.
At a high level; everyone should keep in mind:
If I decide to leave the company tomorrow; what am I leaving behind?
- Would someone else WANT to walk into my role and would they be able to pick up where I am now?
- If I were that person; would I want to pick up tomorrow where I left off today?
- If I were replacing myself, would I feel comfortable walking into my tasks within a day? A week? (etc)
Each of us (and every person in the world!) is going to have personal quirks; things that are unique to them and are not things that "most other people" are going to pick up.
- Identifying these within yourself and understanding "where your edges are" is an important tool in balancing process and procedure
- There may be no value (though sometimes there is!) in adding your own spin to your documentation / notes; To many this is just extra noise someone will need to parse through to catch up
Extend this idea further:
- if I were hit-by-a-bus and killed tomorrow; what would someone else stepping into my shoes need to know to continue with the tasks I'm working on?
- How would they know what tasks I'm working on?
- Who would communicate this information to that person?
- What information would they need above and beyond the information in each task to be able to accomplish it?
- Some of this is notes; some of this is wiki documentation; some of this is team communication!
If I were hit by a bus and someone else was stepping into my shoes; how much work does the company have to put in to get them to where I am now?
- This is a very important metric and ultimately determines how you're viewed by a business; someone who could leave at any moment but leaves nothing behind has created little long-term value.
- Someone who could leave at any moment but overall work in their group/department would continue in 1-2 days with no major interruptions in operations: is someone who creates a lot of persistable value for the company!
Overall; these are ideas to explore in your own professional development and are (in my opinion and experience!) valuable tools to assist each of us in personal growth as well as benefiting the company AND the people around us.
One of the major things to keep in mind here is that some view this overall approach as “derogatory” or that:
“If I document how I work; I’m costing myself value as the company can simply replace me and continue where I am now”.
I’m personally and professionally very against this idea; and I'm not alone in thinking this.
The people who create, adhere to processes and create value that helps the company; are not people to be replaced: they are people to be promoted.
Thinking about the long term, what you will leave behind and what value you can create now that will pay off long term is something that any competent business leader is looking for and if the cost-benefit of a proposed solution yields positive revenue in the foreseeable future: is generally willing to consider.
Long term; few people want to do the same thing every day; which is why I (and nearly every half-decent employer I’ve had the privilege of knowing in the last 20 years!) hugely appreciate and find value in these sorts of people.
IMO “cornering knowledge” and “protecting process” are the things I (personally) want the least of in life; I want each and every person to grow and develop; and to be able to teach others what worked; what didn’t; and why they decided to do what they did to accomplish all the wonderful things!
 = For the record: this is not something I regularly achieve. It’s a very fine line one has to walk to be able to even approach this idea being true and to be completely honest: it’s a lot of work that ultimately does not always match reality. Some processes/ideas/concepts/work are simply not valuable enough to bother persisting; and some are viewed as unimportant but would have really benefited the company.