Do insurance companies insure themselves?

My wife and I were wondering this this morning. If an insurance department is broken in to/has a fire/etc, do they cover themselves?
Answers:
Almost adjectives very roomy companies, including insurance companies, self insure themselves for things like this.

Smaller businesses similar to small agents, for example, would buy an insurance policy.

But big insurers do buy a product called "re-insurance" which is insurance for hulking claims so that the insurer only have to pay subdivision of a large claim and another part of the pack of it is paid by the 'reinsurer.'

Other Answers:
Insurance companys are similar to car rental companys and as such are self inusred, They enjoy a trust/policy that protects them from damage relating to fire etc. prudental authortys control these trust funds if parliament regulations require
Insurance companies will purchase what is called reinsurance. The reinsurance will provide coverage if total amount of claims exceeds a correct amount.
Yes they do. Not only do they insure their own assets near other companies, they also share part of their risks near other companies.

Reinsurance as Rich described above.