Consolidated Statements of Earnings - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenues:      
Sales and service revenues $ 175,445    
Total revenues 247,837 $ 239,933 $ 215,114
Investment and derivative contract gains (losses):      
Investment gains (losses) (22,155) 1,410 7,553
Derivative contract gains (losses) (300) 718 751
Investment and derivative gains/losses (22,455) 2,128 8,304
Costs and expenses:      
Interest expense 3,853 4,386 3,741
Total costs and expenses 219,214 221,237 190,860
Earnings before income taxes and equity method earnings (losses) 6,168 20,824 32,558
Equity method earnings (losses) (2,167) 3,014 1,109
Earnings before income taxes 4,001 23,838 33,667
Income tax expense (benefit) (321) (21,515) 9,240
Net earnings 4,322 45,353 24,427
Earnings attributable to noncontrolling interests 301 413 353
Net earnings attributable to Berkshire Hathaway shareholders $ 4,021 $ 44,940 $ 24,074
Equivalent Class A [Member]      
Costs and expenses:      
Net earnings per average equivalent share $ 2,446 $ 27,326 $ 14,645
Average equivalent shares outstanding 1,643,795 1,644,615 1,643,826
Equivalent Class B [Member]      
Costs and expenses:      
Net earnings per average equivalent share [1] $ 1.63 $ 18.22 $ 9.76
Average equivalent shares outstanding 2,465,692,368 2,466,923,163 2,465,739,654
Insurance and Other [Member]      
Revenues:      
Insurance premiums earned $ 57,418 $ 60,597 $ 45,881
Sales and service revenues 133,336 130,343 123,053
Leasing revenues 5,732 2,452 2,553
Interest, dividend and other investment income 7,678 6,536 6,180
Total revenues 204,164 199,928 177,667
Costs and expenses:      
Insurance losses and loss adjustment expenses 39,906 48,891 30,906
Life, annuity and health insurance benefits 5,699 5,618 5,131
Insurance underwriting expenses 9,793 9,321 7,713
Cost of sales and services 106,083 104,343 97,867
Cost of leasing 4,061 1,455 1,335
Selling, general and administrative expenses 18,238 19,189 17,973
Interest expense 1,035 1,132 1,099
Total costs and expenses 184,815 189,949 162,024
Railroad [Member]      
Revenues:      
Total revenues 23,703 21,080 19,683
Costs and expenses:      
Freight rail transportation expenses 16,045 14,031 13,134
Utilities and Energy [Member]      
Revenues:      
Sales and service revenues 15,555 15,155 14,621
Costs and expenses:      
Cost of sales and other expenses 11,641 10,772 10,471
Railroad, Utilities and Energy [Member]      
Revenues:      
Service revenues and other income 4,415 3,770 3,143
Total revenues 43,673 40,005 37,447
Costs and expenses:      
Other expenses 3,895 3,231 2,589
Interest expense 2,818 3,254 2,642
Total costs and expenses $ 34,399 $ 31,288 $ 28,836
[1] Class B shares are economically equivalent to one-fifteen-hundredth of a Class A share. Accordingly, net earnings per average equivalent Class B share outstanding is equal to one-fifteen-hundredth of the equivalent Class A amount. See Note 21.