Having glimpsed behind the curtain at some organizations risk/exposure management I would bet theres some web of self insured/high deductible, traditional insurance, and reinsurance to limit exposure.

Back in the dark ages/before I was born one of the "ugly truths", if I am recalling correctly the history I've read, was that the way AA insured their DC-10s they actually recouped more than the replacement cost through insurance proceeds on a few of their accidents/DBR incidents with that type.