I am trying to find detailed stock data for the last few years (the
longer, the better). It is easy to find charts, but is there a way to
get detailed data in an accesible format (ie, CSV or anything that you
work with, not just some proprietary format) that shows stock prices
for a range of stocks (the more the better) for the last few years?
And preferably, the
ability to get detailed information for throughout the day, not just
the closing price.

If you want these things; chances are you will have to pay for it. 
For intraday prices, thebest source is a bloomberg terminal.

For good data over the year (assuming you want more than 5 or so which
is easy to find) you should try the Wharton WRDS database. (it can
also give u tons more information like revenue, profts, employees,
different elements of the financial statements and more.)

Thanks!