CHICAGO--(BUSINESS WIRE)--Fitch Ratings has affirmed the Issuer Default Rating (IDR) for Murphy Oil Corporation (NYSE: MUR) at 'BBB-'. The Rating Outlook remains Stable. Fitch affirms the following ratings: Murphy Oil Corporation: --Issuer Default Rating (IDR) at 'BBB-'; --Senior unsecured notes at 'BBB-'; --Senior unsecured revolver at 'BBB-'. Approximately $3.28 billion in balance sheet debt including capitalized leases is affected by today's rating action. KEY RATING DRIVERS MUR's ratings ar