As far as I know the entire information on this matter is provided by the broker on its website. Perhaps, it's placed in "deposit methods" section, but, if you have asked this question, then I will help you.
Bank/wire transfer is the longest way to withdraw money, because it has to pass through several procedures before they get into your account. The broker sends the request to acquirer bank, then after getting this request this bank start the procedure of processing the transaction, sends the request to the issuing bank, and only then you will be able to receive your funds in case there will be no mistakes during processing. It may take up to 7 business days, because banks, obviously, don't process transactions on weekends. I'd advise you to pay attention to some other payment methods, they are substantially faster.

Bank transfer is the most time-consuming withdrawal method, but at the same time it's the most reliable especially if you are planning to withdraw big amounts. The bigger the requested amount the longer you need to wait, even for a week.