"What would I do if I got off a bus, and had to find a job?" Jay Reinke poses this question in the early going of "The Overnighters." It is not entirely existential; this documentary is set in 2013, as the oil fracking boom arrives in Williston, North Dakota. Reinke, pastor of Concordia Lutheran Church, offers lodging to dozens of transient, economically disadvantaged laborers from across the country and around the world seeking the opportunity to better their lives and those of their families. In the name of Christian compassion, vehicles jam the parking lot, cots and sleeping bags line the offices and hallways, and Reinke's cell phone buzzes at all hours, to the detriment of his family life. Functioning (sometimes concurrently) as spiritual guide, social worker, and psychologist, he's a peppy presence when we first meet him: a rumpled, chipper Tim Gunn of the cloth, peering benevolently over lowered spectacles and—perhaps too accommodatingly—extending good will to all comers.