I went to Kraken after searching around for an exchange that I can buy bitcoin with.
So is I.D or documents need to buy bitcoin on their exchange?
All the ones that I have visited including Poloniex asked for Identity Verification Process (KYC) in order to even use their site.
Be sure to not use pseudonym but a real name (they "verify" if the name is real or not), since they are "forced" they may ask you for ID if they think that your name is not real, even though if you verify your account through phone verification.
Even though there is a large trade volume, don't know I don't prefer to trade there, I prefer more poloniex and yobit.