Subsequent Event Subsequent Event

3 Months Ended

Mar. 31, 2017

Subsequent Event [Line Items]

Subsequent Events [Text Block]

Note 20. Subsequent Event

On May 2, 2017, OneBeacon announced it had entered into a definitive agreement to be acquired by Intact Financial Corporation in an all-cash transaction for $18.10 per share, or roughly 1.65x tangible book value (the “Transaction”).  In addition, White Mountains entered into a definitive agreement to vote its shares of OneBeacon Ltd. in favor of the “Transaction”. White Mountains owns 75.7% of OneBeacon’s outstanding common shares, representing 96.9% of the voting power. White Mountains expects to receive gross proceeds of $1.3 billion from the Transaction, which is expected to close in the fourth quarter of 2017. It is subject to regulatory approval and other customary closing conditions.