An apparatus is provided for processing a document traveling along a document path within a document validator. The such apparatus includes a disk where a periphery of the disk extends into the document path of the document validator, a support shaft that passes through a center hole of the disk, the shaft loosely supporting the disk and allowing the disk to rotate around the shaft in a predominant plane of the disk and to freely move in the predominant plane of the disk in a direction that is perpendicular to a longitudinal axis of the shaft and a resilient member that biases the disk into the document path to engage a side edge of the document when the document is misaligned with the document path as it travels along the document path thereby retarding forward movement of the side edge and rotation of the document into alignment with the document path.