Doc existed and some installers were giving it out, at least three years ago, when I got my service for Florida. You can still find it ouline.
For example see this location for Voicemail manuals
https://www.verizon.com/support/residential/phone/homephone/calling+features/using+calling+features/general/128801.htm
Similarly off the support pages you can find the manuals for your FIOS devices. I don't think they have any manuals up for the Onts, but various routers, DVR, and STB can be found.
If you had something printed, it probably would be outdated before most people decided to look at it. There is plenty of answers online in the support section, in the inhome agent, on channel 131 and of course this forum. Some of those places do have some docs you can print out or read online and save a tree.