Hi moosa27,
Thanks for the question. A single gift of $16,000 or $32,000 total from both you parents qualifies for the annual gift exclusion. A letter from your parents and a copy of the bank statement may be enough. However, if your parents give more than that in a single year, they will be required to file a gift tax return on Form 709, assuming they are American citizens. A detailed properly filed Form 709 would provide a lot of documentation for you in the event of an audit.
Here is a link to the IRS site about Gift Tax with many other helpful l inks. FAQs for Gifting.
If you need any additional information feel free to follow up.
