bent, broken transmission or engine mount!
I had the same thing from my minor accident with the exact same symptoms. also check your body mounts and see if they are straight or crooked, could also have pushed your frame back out of alignment.
my drivers side frame rail was pushed back and up got that straightened out and then had the exact vibes you describe which were remedied with a new motor mount and transmission mount. now I have a highway speed vibration that nobody can figure out, all I know it's somewhere in the driveline and have replaced everything with a complete coil lift including driveshafts, arms, springs, shocks, trackbars, tie rods, ball joints, wheels balanced, aligned and nothing or nobody can get this vibration out. it did it stock and with everything replaced remains.
Anyway thats my rant but the vibration at idle was cured with new motor and transmission mounts