Why don't you like the idea? That's what the banking system is for, and transfers on this scale are routine for wealthy individuals. The money won't just vanish into the ether unless a) you send it to a third-world bank, or b) the financial system goes down in the next 72 hours. Triple check that the sender has the correct account numbers and so on, and ask for a confirmation screen shot or transfer number if it makes you feel better.
Let the receiving bank know to expect the wire, the source of the funds, and any supporting documentation (share purchase agreement, deed of transfer if selling a property, brokerage statement, etc). If you're in this category you'll likely already have a relationship with your banker and they'll have satisfied themselves as to your source of wealth already. If its a new relationship, give them a heads up. I didn't do this once (for an order of magnitude less "large") and had to hire a lawyer as some clerk hit the "suspicious" button and it got stuck in bureaucratic hell despite being legit.