Significant accounting policies and practices (Policies)	3 Months Ended
Mar. 31, 2012
New accounting pronouncements	As of January 1, 2012, we adopted FASB Accounting Standards Update (“ASU”) 2010-26, “Accounting for Costs Associated with Acquiring or Renewing Insurance Contracts.” ASU 2010-26 specifies that only direct incremental costs associated with successful efforts in acquiring or renewing of insurance contracts should be capitalized and amortized over the policy term. All other costs are required to be expensed as incurred. Capitalized costs include certain advertising costs if the primary purpose of the advertising is to elicit sales to customers who could be shown to have responded directly to the advertising and the probable future revenues generated from the advertising are in excess of expected future costs to be incurred in realizing those revenues. Berkshire is adopting ASU 2010-26 on a prospective basis. The impact of the adoption of this new standard primarily relates to certain advertising costs of GEICO, which were capitalized prior to the adoption of ASU 2010-26, but are no longer eligible to be capitalized. The adoption of this new standard did not have a material effect on our Consolidated Financial Statements. As of January 1, 2012, we also adopted ASU 2011-04, “Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs.” As a result of adopting ASU 2011-04, we have expanded our fair value disclosures. In December 2011, the FASB issued ASU 2011-11 “Disclosures about Offsetting Assets and Liabilities.” ASU 2011-11 enhances disclosures surrounding offsetting (netting) assets and liabilities. The standard applies to financial instruments and derivatives and requires companies to disclose both gross and net information about instruments and transactions eligible for offset in financial statements and instruments and transactions subject to a master netting arrangement. ASU 2011-11 is effective retrospectively for Berkshire beginning January 1, 2013. We are currently evaluating the effect this standard will have on our Consolidated Financial Statements.

As of January 1, 2012, we adopted FASB Accounting Standards Update (“ASU”) 2010-26, “Accounting for Costs Associated with Acquiring or Renewing Insurance Contracts.” ASU 2010-26 specifies that only direct incremental costs associated with successful efforts in acquiring or renewing of insurance contracts should be capitalized and amortized over the policy term. All other costs are required to be expensed as incurred. Capitalized costs include certain advertising costs if the primary purpose of the advertising is to elicit sales to customers who could be shown to have responded directly to the advertising and the probable future revenues generated from the advertising are in excess of expected future costs to be incurred in realizing those revenues. Berkshire is adopting ASU 2010-26 on a prospective basis. The impact of the adoption of this new standard primarily relates to certain advertising costs of GEICO, which were capitalized prior to the adoption of ASU 2010-26, but are no longer eligible to be capitalized. The adoption of this new standard did not have a material effect on our Consolidated Financial Statements.

As of January 1, 2012, we also adopted ASU 2011-04, “Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs.” As a result of adopting ASU 2011-04, we have expanded our fair value disclosures.

In December 2011, the FASB issued ASU 2011-11 “Disclosures about Offsetting Assets and Liabilities.” ASU 2011-11 enhances disclosures surrounding offsetting (netting) assets and liabilities. The standard applies to financial instruments and derivatives and requires companies to disclose both gross and net information about instruments and transactions eligible for offset in financial statements and instruments and transactions subject to a master netting arrangement. ASU 2011-11 is effective retrospectively for Berkshire beginning January 1, 2013. We are currently evaluating the effect this standard will have on our Consolidated Financial Statements.