When a member puts their money into Solidarity, it's protected against loss up to $100,000 by the NCUA (National Credit Union Administration).  IRAs are insured up to $250,000.  Essentially, that's the same thing the FDIC offers to customers at any bank in the U.S.  The insurance is there to protect members (depositors at banks) from the loss of their principal deposit up to $100,000 in the case of a failure or serious financial impairment of the financial institution.

For more information about the NCUA, just visit the NCUA website.