  Demonstrating nonclassical effects over longer and longer distances is
essential for both quantum technology and fundamental science. The main
challenge is loss of photons during propagation, because considering only those
cases where photons are detected opens a "detection loophole" in security
whenever parties or devices are untrusted. Einstein-Podolsky-Rosen (EPR)
steering is equivalent to an entanglement-verification task in which one party
(device) is untrusted. We derive arbitrarily loss-tolerant tests, enabling us
to perform a detection-loophole-free demonstration of EPR-steering with parties
separated by a coiled 1 km optical fiber, with a total loss of 8.9 dB (87%).
