This just means they don't insure and instead absorb losses. AFAIK they don't even set aside a pool of money like corporate self-insurance tends to do.

>CRS missions appear to carry commercial insurance

This is to (partially) cover the losses to the commercial space companies, since NASA withholds money in the event of a failure. None of it covers the payload. (Actually at least in Orbital's case they get paid a portion of the CRS contract, since there's technically two milestones – ignition/liftoff and mission success. They lose out on the latter.[1])

[1] http://spacenews.com/42658orbital-sciences-entitled-to-parti...