 OLDWICK, N.J.--BUSINESS WIRE-- insurance--AM Best has upgraded the Financial Strength Rating to A- Excellent from B Good and the Long-Term Issuer Credit Rating Long-Term ICR to a- Excellent from bbb Good of Illinois Casualty Company ICC. Concurrently, AM Best has upgraded the Long-Term ICR to bbb- Good from bb Good of ICC Holdings, Inc. ICCH NASDAQ: ICCH, the publicly traded holding company that owns 100 of ICC. The outlook of these Credit Ratings ratings is stable. Bot 