To detach the tty without exiting the shell, use the escape sequence Ctrl+P followed by Ctrl+Q. More details here.
Additional info from this source:
- docker run -t -i → can be detached with
^P^Qand reattached with docker attach - docker run -i → cannot be detached with
^P^Q; will disrupt stdin - docker run → cannot be detached with
^P^Q; can SIGKILL client; can reattach with docker attach