I do put my insurance policies in my A-Z file. Upon receipt of an updated policy the old one is filed in the monthly.
Statements stay in the 12 hanging files Jan - Dec that are in front of my A-Z reference files. As far as credit card information, I used to keep files for them that kept the terms and conditions and privacy notices for each account. But frankly, because they change the terms nearly every month, and privacy policies don't really protect our privacy but state how they violate it, I just review those and toss them.
Any kind of statement or bill that I get such as credit card and bank statements also go in the monthly hanging files and not in the A-Z reference section in my case.
I've found a chronological system works well for me for these monthly recurring items, cuts down on filing time, reduces the chance filing will hold up my system and at the end of the year, all of my financial statements, receipts, etc are in one financial file for the complete year.
In email, I keep receipts for electronic payments in my archive folder which is searchable.
If you are a lazy filer, a chronological filing system where everything new goes in the back of the file is super quick way to file. Most stuff we keep we rarely have to refer to anyway. If it's important, you think it might be important, make a reference file. Look at each piece of paper as it comes through and ask yourself how many times you have ever looked in your fiing system for this type of statement or whatever and if you can't remember, file chronologically. If you see yourself digging for something in your chronological file for something on a regular basis, make a reference file for it.
For my project files that I am currently working on, I use green file folders and file them in my project files. Things that might go into A-Z reference files, I put in generic manilla folders so at a glance I can tell where it goes.
Hope that helps