CHICAGO--(BUSINESS WIRE)--Fitch Ratings has affirmed the Issuer Default Rating (IDR) of StanCorp Financial Group, Inc. (SFG) at 'BBB+' and the Insurer Financial Strength (IFS) ratings of its life insurance subsidiaries at 'A'. The Rating Outlook is Stable. A full list of rating actions follows at the end of this release. KEY RATING DRIVERS The rating action follows the announcement that SFG has agreed to be acquired by Japan-based Meiji Yasuda Life Insurance Company (MYL) in a transaction value