Close. Docker for Mac runs in a paravirtual environment using Hyperkit, which uses Apple's Hypervisor.framework. At least that was true a couple years ago. A couple years before that, Docker Machine and boot2docker ran on hypervisor of choice (e.g. Virtualbox).

If you get a chance, Hyperkit can be fun to play with. I was able to write a bash script that downloads Hyperkit andba Debian ISO, and from that boot a running instance of Debian. It was an interesting exercise.