It depends on the mutual mass of the bodies. If the attractive force between two bodies is large enough, then they will continue to orbit each other.<br /><br />This is shown by Galaxies orbiting larger galaxies in our Local Group, such as the LMC and SMC and the satellite galaxies of M31. There is no upper limit to the orbiting mass between two gravitational masses.<br /><br />Two sufficiently massive black holes could orbit each other at hundreds of millions of light years, just as our sun orbits the galaxy's center.<br /><br />No large masses have been detected which are large enough to orbit the sun at those distances.<br /><br />But a very large and massive dark star or black hole could easily orbit the sun in a stable orbit if its mass were large enough.<br /><br />so the actual statement needs to be, "No masses large enough to orbit the sun beyond 100,000 AU have been detected". And are probably unlikely to exist, too, as such large masses would have been very probably been detected by our telescopes and their gravitational influences on the outer planets.