Contingencies and Subsequent Event	9 Months Ended
Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Subsequent Event	Note 21. Contingencies and Subsequent Event We are parties in a variety of legal actions that routinely arise out of the normal course of business, including legal actions seeking to establish liability directly through insurance contracts or indirectly through reinsurance contracts issued by Berkshire subsidiaries. Plaintiffs occasionally seek punitive or exemplary damages. We do not believe that such normal and routine litigation will have a material effect on our financial condition or results of operations. Berkshire and certain of its subsidiaries are also involved in other kinds of legal actions, some of which assert or may assert claims or seek to impose fines and penalties. We believe that any liability that may arise as a result of other pending legal actions will not have a material effect on our consolidated financial condition or results of operations. In 2016, NICO entered into a definitive agreement to acquire Medical Liability Mutual Insurance Company, (“Medical Liability Mutual”), a writer of medical professional liability insurance domiciled in New York. The acquisition price was approximately $2.5 billion. The acquisition involved the conversion of Medical Liability Mutual from a mutual company to a stock company. The closing of the transaction was subject to various regulatory approvals, customary closing conditions and the approval of the Medical Liability Mutual policyholders eligible to vote on the proposed demutualization and sale. The acquisition closed on October 1, 2018, at which time, Medical Liability Mutual’s name was changed to the MLMIC Insurance Company (“MLMIC”). The results of MLMIC will be included in Berkshire’s consolidated results beginning as of that date. As of the acquisition date, the preliminary fair values of MLMIC’s assets were approximately $6.3 billion, consisting primarily of cash and investments, and liabilities were approximately $3.8 billion, consisting primarily of unpaid losses and loss adjustment expenses and unearned insurance premiums. We believe goodwill arising from this acquisition will be insignificant. MLMIC’s premiums earned for the first nine months of 2018 were approximately $300 million.

Note 21. Contingencies and Subsequent Event

We are parties in a variety of legal actions that routinely arise out of the normal course of business, including legal actions seeking to establish liability directly through insurance contracts or indirectly through reinsurance contracts issued by Berkshire subsidiaries. Plaintiffs occasionally seek punitive or exemplary damages. We do not believe that such normal and routine litigation will have a material effect on our financial condition or results of operations. Berkshire and certain of its subsidiaries are also involved in other kinds of legal actions, some of which assert or may assert claims or seek to impose fines and penalties. We believe that any liability that may arise as a result of other pending legal actions will not have a material effect on our consolidated financial condition or results of operations.

In 2016, NICO entered into a definitive agreement to acquire Medical Liability Mutual Insurance Company, (“Medical Liability Mutual”), a writer of medical professional liability insurance domiciled in New York. The acquisition price was approximately $2.5 billion. The acquisition involved the conversion of Medical Liability Mutual from a mutual company to a stock company. The closing of the transaction was subject to various regulatory approvals, customary closing conditions and the approval of the Medical Liability Mutual policyholders eligible to vote on the proposed demutualization and sale. The acquisition closed on October 1, 2018, at which time, Medical Liability Mutual’s name was changed to the MLMIC Insurance Company (“MLMIC”). The results of MLMIC will be included in Berkshire’s consolidated results beginning as of that date. As of the acquisition date, the preliminary fair values of MLMIC’s assets were approximately $6.3 billion, consisting primarily of cash and investments, and liabilities were approximately $3.8 billion, consisting primarily of unpaid losses and loss adjustment expenses and unearned insurance premiums. We believe goodwill arising from this acquisition will be insignificant. MLMIC’s premiums earned for the first nine months of 2018 were approximately $300 million.