Diversity case where RLI sued PIIL and USF to recover part of what RLI paid to settle a nursing home case. The nursing home and all three insurance companies settled the underlying claim in 2003 for $3.9 million. The issue on summary judgment was allocation of the settlement amount among the insurers. Applying Texas law, the court found that RLI (the excess carrier) was entitled to judgment against the primary carriers because each was required to exhaust their limits before the excess carrier’s duty to indemnify was triggered.