Third Party Reinsurance

3 Months Ended

Mar. 31, 2014

Reinsurance Disclosures [Abstract]

Third Party Reinsurance

Third Party Reinsurance

In the normal course of business, White Mountains’s insurance and reinsurance subsidiaries may seek to limit losses that may arise from catastrophes or other events by reinsuring with third party reinsurers. White Mountains remains liable for risks reinsured in the event that the reinsurer does not honor its obligations under reinsurance contracts.

OneBeacon

At March 31, 2014, OneBeacon had $3.0 million and $80.1 million of reinsurance recoverables on paid and unpaid losses. At December 31, 2013, OneBeacon had $9.7 million and $80.2 million of reinsurance recoverables on paid and unpaid losses. The reinsurance balances associated with the Runoff Business are included in discontinued operations (see Note 15). Reinsurance contracts do not relieve OneBeacon of its obligation to its policyholders. OneBeacon is selective with its reinsurers, placing reinsurance with only those reinsurers having a strong financial condition. OneBeacon monitors the financial strength and ratings of its reinsurers on an ongoing basis. Uncollectible amounts related to the ongoing specialty business historically have not been significant.

Effective January 1, 2014, OneBeacon entered into reinsurance treaties to provide coverage for the 2014 crop year. OneBeacon purchased an aggregate stop loss on its multiple peril crop insurance portfolio, providing 48.5% of coverage in excess of a 101.5% loss ratio on premiums covered by the contract and a separate aggregate stop loss providing 80.0% of coverage in excess of a 100.0% loss ratio on its crop-hail portfolio.

Sirius Group

At March 31, 2014, Sirius Group had $12.2 million and $344.8 million of reinsurance recoverables on paid and unpaid losses that will become recoverable if claims are paid in accordance with current reserve estimates. At December 31, 2013, Sirius Group had $15.7 million and $347.9 million of reinsurance recoverables on paid and unpaid losses. Because retrocessional reinsurance contracts do not relieve Sirius Group of its obligation to its insureds, the collectability of balances due from Sirius Group’s reinsurers is important to its financial strength. Sirius Group monitors the financial strength and ratings of retrocessionaires on an ongoing basis. Uncollectible amounts historically have not been significant.