Berkshire Hathaway (BRK-B) 10-K 25 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 14, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	BRKA
Entity Registrant Name	BERKSHIRE HATHAWAY INC.
Entity Central Index Key	1,067,983
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 367,009,000,000
Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		725,807
Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,372,751,831

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2018		Dec. 31, 2017
ASSETS
Investments in fixed maturity securities		$ 19,898		$ 21,353
Investments in equity securities		172,757	[1]	170,540	[2]
Loans and finance receivables		16,280		13,748
Inventories		19,069		17,366
Goodwill		81,025		81,258
Deferred charges under retroactive reinsurance contracts		14,104		15,278
Total assets		707,794		702,095
LIABILITIES
Income taxes, principally deferred		51,375		56,607
Unpaid losses and loss adjustment expenses		68,458		61,122
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts		41,834		42,937
Total liabilities		355,294		350,141
Shareholders' equity:
Common stock		8		8
Capital in excess of par value		35,707		35,694
Accumulated other comprehensive income		(5,015)		58,571
Retained earnings		321,112		255,786
Treasury stock, at cost		(3,109)		(1,763)
Berkshire Hathaway shareholders' equity		348,703		348,296
Noncontrolling interests		3,797		3,658
Total shareholders' equity		352,500		351,954
Total liabilities and shareholders' equity		707,794		702,095
Insurance and Other [Member]
ASSETS
Cash and cash equivalents	[3]	27,749		28,673
Short-term investments in U.S. Treasury Bills		81,506		84,371
Investments in fixed maturity securities		19,898		21,353
Investments in equity securities		172,757		170,540
Equity method investments		17,325		21,024
Loans and finance receivables		16,280		13,748
Other receivables		31,564		29,392
Inventories		19,069		17,366
Property, plant and equipment		20,628		19,868
Equipment held for lease		14,298		10,167
Goodwill		56,323		56,478
Other intangible assets		31,499		32,518
Deferred charges under retroactive reinsurance contracts		14,104		15,278
Other		9,307		9,391
Total assets		532,307		530,167
LIABILITIES
Unpaid losses and loss adjustment expenses		68,458		61,122
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts		41,834		42,937
Unearned premiums		18,093		16,040
Life, annuity and health insurance benefits		18,632		17,608
Other policyholder liabilities		7,675		7,654
Accounts payable, accruals and other liabilities		25,776		24,569
Derivative contract liabilities		2,452		2,172
Aircraft repurchase liabilities and unearned lease revenues		4,593
Notes payable and other borrowings		34,975		40,409
Total liabilities		222,488		212,511
Railroad, Utilities and Energy [Member]
ASSETS
Cash and cash equivalents	[3]	2,612		2,910
Receivables		3,666		3,531
Property, plant and equipment		131,780		128,184
Goodwill		24,702		24,780
Regulatory assets		3,067		2,950
Other		9,660		9,573
Total assets		175,487		171,928
LIABILITIES
Accounts payable, accruals and other liabilities		11,410		11,334
Regulatory liabilities		7,506		7,511
Notes payable and other borrowings		62,515		62,178
Total liabilities		$ 81,431		$ 81,023
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.5 billion; Apple Inc. - $40.3 billion; Bank of America Corporation - $22.6 billion; The Coca-Cola Company - $18.9 billion and Wells Fargo & Company - $20.7 billion).
[2]	Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company - $15.1 billion; Apple Inc. - $28.2 billion; Bank of America Corporation - $20.7 billion; The Coca-Cola Company - $18.4 billion and Wells Fargo & Company - $29.3 billion).
[3]	Cash and cash equivalents includes U.S. Treasury Bills with maturities of three months or less when purchased of $3.9 billion at December 31, 2018 and $5.7 billion at December 31, 2017.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Billions	Dec. 31, 2018	Dec. 31, 2017
U.S. Treasury Bills [Member]
Cash equivalents	$ 3.9	$ 5.7

Consolidated Statements of Earn

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.

Consolidated Statements of Ea_2

Consolidated Statements of Earnings (Parenthetical)	12 Months Ended
	Dec. 31, 2018
Class B [Member]
Economic equivalent of Class B share to Class A share	0.0667%

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 4,322	$ 45,353	$ 24,427
Other comprehensive income:
Net change in unrealized appreciation of investments	(185)	30,450	13,858
Applicable income taxes	31	(10,566)	(4,846)
Reclassification of investment appreciation in net earnings	(253)	(1,399)	(6,820)
Applicable income taxes	53	490	2,387
Foreign currency translation	(1,531)	2,364	(1,541)
Applicable income taxes	62	(95)	66
Prior service cost and actuarial gains/losses of defined benefit pension plans	(571)	225	354
Applicable income taxes	143	(45)	(187)
Other, net	(12)	(9)	(17)
Other comprehensive income, net	(2,263)	21,415	3,254
Comprehensive income	2,059	66,768	27,681
Comprehensive income attributable to noncontrolling interests	249	555	291
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 1,810	$ 66,213	$ 27,390

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Common stock and capital in excess of par value	Accumulated other comprehensive income	Retained earnings	Treasury stock	Noncontrolling interests
Beginning Balance at Dec. 31, 2015	$ 257,696	$ 35,628	$ 33,982	$ 186,772	$ (1,763)	$ 3,077
Net earnings	24,427			24,074		353
Other comprehensive income, net	3,254		3,316			(62)
Issuance of common stock	119	119
Transactions with noncontrolling interests	(68)	(58)				(10)
Ending Balance at Dec. 31, 2016	285,428	35,689	37,298	210,846	(1,763)	3,358
Net earnings	45,353			44,940		413
Other comprehensive income, net	21,415		21,273			142
Issuance of common stock	76	76
Transactions with noncontrolling interests	(318)	(63)				(255)
Ending Balance at Dec. 31, 2017	351,954	35,702	58,571	255,786	(1,763)	3,658
Adoption of new accounting pronouncements	(70)		(61,375)	61,305
Net earnings	4,322			4,021		301
Other comprehensive income, net	(2,263)		(2,211)			(52)
Issuance (acquisition) of common stock	(1,287)	59			(1,346)
Transactions with noncontrolling interests	(156)	(46)				(110)
Ending Balance at Dec. 31, 2018	$ 352,500	$ 35,715	$ (5,015)	$ 321,112	$ (3,109)	$ 3,797

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Cash flows from operating activities:
Net earnings	$ 4,322		$ 45,353		$ 24,427
Adjustments to reconcile net earnings to operating cash flows:
Investment gains/losses	22,155		(1,410)		(7,553)
Depreciation and amortization	9,779		9,188		8,901
Other	2,957		458		(161)
Changes in operating assets and liabilities:
Losses and loss adjustment expenses	3,449		25,027		4,372
Deferred charges reinsurance assumed	1,174		(7,231)		(360)
Unearned premiums	1,794		1,761		968
Receivables and originated loans	(3,443)		(1,990)		(3,302)
Other assets	(1,832)		(1,665)		(373)
Other liabilities	2,002		1,194		1,684
Income taxes	(4,957)		(24,957)		4,044
Net cash flows from operating activities	37,400		45,728		32,647
Cash flows from investing activities:
Purchases of U.S. Treasury Bills and fixed maturity securities	(141,844)		(158,492)		(96,568)
Purchases of equity securities	(43,210)		(20,326)		(16,508)
Sales of U.S. Treasury Bills and fixed maturity securities	39,693		49,327		18,757
Redemptions and maturities of U.S. Treasury Bills and fixed maturity securities	113,045		86,727		26,177
Sales and redemptions of equity securities	18,783		19,512		28,464
Purchases of loans and finance receivables	(1,771)		(1,435)		(307)
Collections of loans and finance receivables	342		1,702		490
Acquisitions of businesses, net of cash acquired	(3,279)		(2,708)		(31,399)
Purchases of property, plant and equipment and equipment held for lease	(14,537)		(11,708)		(12,954)
Other	(71)		(3,608)		(377)
Net cash flows from investing activities	(32,849)		(41,009)		(84,225)
Cash flows from financing activities:
Changes in short term borrowings, net	(1,943)		2,079		130
Acquisition of treasury stock	(1,346)
Other	(343)		(121)		112
Net cash flows from financing activities	(5,812)		(1,398)		12,791
Effects of foreign currency exchange rate changes	(140)		248		(172)
Increase (decrease) in cash and cash equivalents and restricted cash	(1,401)		3,569		(38,959)
Cash and cash equivalents and restricted cash at beginning of year	32,212		28,643		67,602
Cash and cash equivalents and restricted cash at end of year	30,811		32,212		28,643
Restricted cash, included in other assets at end of year	450		629		595
Insurance and Other [Member]
Cash flows from financing activities:
Proceeds from borrowings	2,409		2,645		14,172
Repayments of borrowings	(7,395)		(5,465)		(2,577)
Cash and cash equivalents at end of year	27,749	[1]	28,673	[1]	24,109
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	7,019		3,013		3,077
Repayments of borrowings	(4,213)		(3,549)		(2,123)
Cash and cash equivalents at end of year	$ 2,612	[1]	$ 2,910	[1]	$ 3,939
[1]	Cash and cash equivalents includes U.S. Treasury Bills with maturities of three months or less when purchased of $3.9 billion at December 31, 2018 and $5.7 billion at December 31, 2017.

Significant accounting policies

Significant accounting policies and practices	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant accounting policies and practices	(1) Significant accounting policies and practices (a) Nature of operations and basis of consolidation Berkshire Hathaway Inc. (“Berkshire”) is a holding company owning subsidiaries engaged in a number of diverse business activities, including insurance and reinsurance, freight rail transportation, utilities and energy, manufacturing, service, retailing and finance. In these notes the terms “us,” “we,” or “our” refer to Berkshire and its consolidated subsidiaries. Further information regarding our reportable business segments is contained in Note 26. Information concerning significant business acquisitions completed over the past three years appears in Note 2. The Consolidated Financial Statements for periods before 2018 reflect reclassifications to conform to 2018 presentations. Most significantly, line items previously reported under the sub-caption The accompanying Consolidated Financial Statements include the accounts of Berkshire consolidated with the accounts of all subsidiaries and affiliates in which we hold a controlling financial interest as of the financial statement date. Normally a controlling financial interest reflects ownership of a majority of the voting interests. We consolidate variable interest entities (“VIE”) when we possess both the power to direct the activities of the VIE that most significantly affect its economic performance, and we (a) are obligated to absorb the losses that could be significant to the VIE or (b) hold the right to receive benefits from the VIE that could be significant to the VIE. Intercompany accounts and transactions have been eliminated. (b) Use of estimates in preparation of financial statements The preparation of our Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. In particular, estimates of unpaid losses and loss adjustment expenses are subject to considerable estimation error due to the inherent uncertainty in projecting ultimate claim costs. In addition, estimates and assumptions associated with the amortization of deferred charges on retroactive reinsurance contracts, determinations of fair values of certain financial instruments and evaluations of goodwill and identifiable intangible assets for impairment require considerable judgment. Actual results may differ from the estimates used in preparing our Consolidated Financial Statements. (c) Cash and cash equivalents and short-term investments in U.S. Treasury Bills Cash equivalents consist of demand deposit and money market accounts and investments with maturities of three months or less when purchased. Short-term investments in U.S. Treasury Bills with remaining maturities exceeding three months at the time of purchase are stated at amortized cost, which approximates fair value. (d) Investments in fixed maturity securities We classify investments in fixed maturity securities at the acquisition date and re-evaluate held-to-maturity available-for-sale available-for-sale. Investment gains and losses arise when fixed maturity securities are sold (as determined on a specific identification basis) or are other-than-temporarily impaired with respect to securities classified as available-for-sale. (e) Investments in equity securities We carry substantially all of our investments in equity securities at fair value and record the subsequent changes in fair values in the Consolidated Statement of Earnings as a component of investment gains/losses. Prior to January 1, 2018, substantially all of our equity security investments were classified as available-for-sale (f) Investments under the equity method We utilize the equity method to account for investments when we possess the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when the investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate that the ability to exercise significant influence is restricted. We apply the equity method to investments in common stock and to other investments when such other investments possess substantially identical subordinated interests to common stock. In applying the equity method, we record the investment at cost and subsequently increase or decrease the carrying amount of the investment by our proportionate share of the net earnings or losses and other comprehensive income of the investee. We record dividends or other equity distributions as reductions in the carrying value of the investment. In the event that net losses of the investee reduce the carrying amount to zero, additional net losses may be recorded if other investments in the investee are at-risk, (g) Receivables Receivables primarily consists of balances due from customers, insurance premiums receivable and reinsurance recoverable on unpaid losses. Receivables are stated net of estimated allowances for uncollectible balances. Allowances for uncollectible balances are provided when it is probable counterparties or customers will be unable to pay all amounts due based on the contractual terms. We write-off (h) Loans and finance receivables Loans and finance receivables are predominantly manufactured housing installment loans. We carry these loans at amortized cost, net of allowances for uncollectible accounts, based on our ability and intent to hold such loans to maturity. Acquisition costs and loan origination and commitment costs paid or fees received along with acquisition premiums or discounts are amortized as yield adjustments over the lives of the loans. Substantially all of our loans and finance receivables are secured by real or personal property or by other assets of the borrower. Allowances for credit losses on loans include estimates of losses on loans currently in foreclosure and losses on loans not currently in foreclosure. We estimate losses on loans in foreclosure based on historical experience and collateral recovery rates. Estimates of losses on loans not currently in foreclosure consider historical default rates, collateral recovery rates and prevailing economic conditions. Allowances for credit losses also incorporate the historical average time elapsed from the last payment until foreclosure. Loans are considered delinquent when payments are more than 30 days past due. We place loans over 90 days past due on nonaccrual status and accrued but uncollected interest is reversed. Subsequent collections on the loans are first applied to the principal and interest owed for the most delinquent amount. We resume interest income accrual once a loan is less than 90 days delinquent. Loans in the foreclosure process are considered non-performing. (i) Derivatives We carry derivative contracts in our Consolidated Balance Sheets at fair value, net of reductions permitted under master netting agreements with counterparties. We record the changes in fair value of derivative contracts that do not qualify as hedging instruments for financial reporting purposes in earnings or by our regulated utilities businesses as regulatory assets or liabilities, as applicable, when inclusion in regulated rates is probable. (j) Fair value measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Alternative valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not acting under duress. Our nonperformance or credit risk is considered in determining the fair value of liabilities. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. (k) Inventories Inventories consist of manufactured goods, goods acquired for resale, homes constructed for sale, and materials consumed in business operations. Manufactured inventory costs include raw materials, direct and indirect labor and factory overhead. We used the last-in-first-out first-in-first-out Non-LIFO (l) Property, plant and equipment We record additions to property, plant and equipment used in operations at cost, which includes asset additions, improvements and betterments. With respect to constructed assets, all materials, direct labor and contract services as well as certain indirect costs are capitalized. Indirect costs include interest over the construction period. With respect to constructed assets of our utility and energy subsidiaries that are subject to authoritative guidance for regulated operations, capitalized costs also include an equity allowance for funds used during construction, which represents the cost of equity funds used to finance the construction of the regulated facilities. See Note 1(t). Normal repairs and maintenance and other costs that do not improve the property, extend the useful life or otherwise do not meet capitalization criteria are charged to expense as incurred. Rail grinding costs related to our railroad properties are expensed as incurred. Depreciation of assets of our regulated utilities and railroad is generally determined using group depreciation methods where rates are based on periodic depreciation studies approved by the applicable regulator. Under group depreciation, a single depreciation rate is applied to the gross investment in a particular class of property, despite differences in the service life or salvage value of individual property units within the same class. When such assets are retired or sold, no gain or loss is recognized. Gains or losses on disposals of all other assets are recorded through earnings. We depreciate property, plant and equipment used by our other businesses to estimated salvage value primarily using the straight-line method over estimated useful lives. Ranges of estimated useful lives of depreciable assets used in our other businesses are as follows: buildings and improvements – 5 to 50 years, machinery and equipment – 3 to 25 years and furniture, fixtures and other – 3 to 15 years. Ranges of estimated useful lives of depreciable assets unique to our railroad business are as follows: track structure and other roadway – 9 to 100 years and locomotives, freight cars and other equipment – 6 to 41 years. Ranges of estimated useful lives of assets unique to our regulated utilities and energy businesses are as follows: utility generation, transmission and distribution systems – 5 to 80 years, interstate natural gas pipeline assets – 3 to 80 years and independent power plants and other assets – 3 to 30 years. We evaluate property, plant and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or when the assets are held for sale. Upon the occurrence of a triggering event, we assess whether the estimated undiscounted cash flows expected from the use of the asset and the residual value from the ultimate disposal of the asset exceeds the carrying value. If the carrying value exceeds the estimated recoverable amounts, we reduce the carrying value to fair value and record an impairment loss in earnings, except with respect to impairment of assets of our regulated utility and energy subsidiaries where the impacts of regulation are considered in evaluating the carrying value. (m) Equipment held for lease We record additions to equipment held for lease at cost. We depreciate equipment held for lease to estimated salvage value primarily using the straight-line method over estimated useful lives ranging from 6 to 35 years. We also evaluate equipment held for lease for impairment consistent with policies for property, plant and equipment. (n) Goodwill and other intangible assets Goodwill represents the excess of the acquisition price of a business over the fair value of identified net assets of that business. We evaluate goodwill for impairment at least annually. When evaluating goodwill for impairment, we estimate the fair value of the reporting unit. There are several methods that may be used to estimate a reporting unit’s fair value, including market quotations, asset and liability fair values and other valuation techniques, including, but not limited to, discounted projected future net earnings or net cash flows and multiples of earnings. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. We amortize intangible assets with finite lives in a pattern that reflects the expected consumption of related economic benefits or on a straight-line basis over the estimated economic lives. Intangible assets with finite lives are reviewed for impairment when events or changes in circumstances indicate that the carrying amount may not be recoverable. Intangible assets with indefinite lives are tested for impairment at least annually and when events or changes in circumstances indicate that, more-likely-than-not, (o) Revenue recognition We earn insurance premiums on prospective property/casualty insurance and reinsurance contracts over the loss exposure or coverage period in proportion to the level of protection provided. In most cases, such premiums are earned ratably over the term of the contract with unearned premiums computed on a monthly or daily pro-rata On January 1, 2018, we adopted Accounting Standards Codification (“ASC”) 606 “Revenues from Contracts with Customers.” Except as described in Note 1(w), our revenue recognition practices for contracts with customers under ASC 606 do not differ significantly from prior practices. Under ASC 606, revenues are recognized when a good or service is transferred to a customer. A good or service is transferred when (or as) the customer obtains control of that good or service. Revenues are based on the consideration we expect to receive in connection with our promises to deliver goods and services to our customers. We manufacture and/or distribute a wide variety of industrial, building and consumer products. Our sales contracts provide customers with these products through wholesale and retail channels in exchange for consideration specified under the contracts. Contracts generally represent customer orders for individual products at stated prices. Sales contracts may contain either single or multiple performance obligations. In instances where contracts contain multiple performance obligations, we allocate the revenue to each obligation based on the relative stand-alone selling prices of each product or service. Sales revenue reflects reductions for returns, allowances, volume discounts and other incentives, some of which may be contingent on future events. In certain customer contracts, sales revenue includes certain state and local excise taxes billed to customers on specified products when those taxes are levied directly upon us by the taxing authorities. Sales revenue excludes sales taxes and value-added taxes collected on behalf of taxing authorities. Sales revenue includes consideration for shipping and other fulfillment activities performed prior to the customer obtaining control of the goods. We also elect to treat consideration for such services performed after control has passed to the customer as sales revenue. Our product sales revenues are generally recognized at a point in time when control of the product transfers to the customer, which coincides with customer pickup or product delivery or acceptance, depending on terms of the arrangement. We recognize sales revenues and related costs with respect to certain contracts over time, primarily from certain castings, forgings and aerostructures contracts. Control of the product units under these contracts transfers continuously to the customer as the product is manufactured. These products generally have no alternative use and the contract requires the customer to provide reasonable compensation if terminated for reasons other than breach of contract. Our energy revenue derives primarily from tariff based sales arrangements approved by various regulatory commissions. These tariff based revenues are mainly comprised of energy, transmission, distribution and natural gas and have performance obligations to deliver energy products and services to customers which are satisfied over time as energy is delivered or services are provided. Our nonregulated energy revenue primarily relates to our renewable energy business. Energy revenues are equivalent to the amounts we have the right to invoice and correspond directly with the value to the customer of the performance to date and include billed and unbilled amounts. Payments from customers are generally due from the customer within 30 days of billing. Rates charged for energy products and services are established by regulators or contractual arrangements that establish the transaction price, as well as the allocation of price amongst the separate performance obligations. When preliminary regulated rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. The primary performance obligation under our freight rail transportation service contracts is to move freight from a point of origin to a point of destination. The performance obligations are represented by bills of lading which create a series of distinct services that have a similar pattern of transfer to the customer. The revenues for each performance obligation are based on various factors including the product being shipped, the origin and destination pair, and contract incentives which are outlined in various private rate agreements, common carrier public tariffs, interline foreign road agreements and pricing quotes. The transaction price is generally a per car amount to transport railcars from a specified origin to a specified destination. Freight revenues are recognized over time as the service is performed because the customer simultaneously receives and consumes the benefits of the service. Revenues recognized represent the proportion of the service completed as of the balance sheet date. Invoices for freight transportation services are generally issued to customers and paid within 30 days or less. Customer incentives, which are primarily provided for shipping a specified cumulative volume or shipping to/from specific locations, are recorded as a reduction to revenue on a pro-rata Other service revenues derive from contracts with customers in which performance obligations are satisfied over time, where customers receive and consume benefits as we perform the services, or at a point in time when the services are provided. Other service revenues primarily derive from real estate brokerage, automotive repair, aircraft management, aviation training, franchising and news distribution services. Leasing revenue is generally recognized ratably over the term of the lease or based on usage, if applicable under the terms of the contract. A substantial portion of our leases are classified as operating leases. Prior to January 1, 2018, we recognized revenues from the sales of fractional ownership interests in aircraft over the term of the related management services agreements, as the transfers of the ownership interests were inseparable from the management services agreements. These agreements also include provisions that require us to repurchase the fractional interest at fair market value at contract termination or upon the customer’s request following the end of a minimum commitment period. ASC 606 provides that such contracts are subject to accounting guidance for lease contracts and not ASC 606. The re-characterization (p) Losses and loss adjustment expenses We record liabilities for unpaid losses and loss adjustment expenses assumed under short duration property/casualty insurance and reinsurance contracts for loss events that have occurred on or before the balance sheet date. Such liabilities represent the estimated ultimate payment amounts without discounting for time value. We base liability estimates on (1) reports of losses from policyholders, (2) individual case estimates and (3) estimates of incurred but not reported losses. Losses and loss adjustment expenses in the Consolidated Statements of Earnings include paid claims, claim settlement costs and changes in estimated claim liabilities. Losses and loss adjustment expenses charged to earnings are net of amounts recovered and estimates of recoverable amounts under ceded reinsurance contracts. Reinsurance contracts do not relieve the ceding company of its obligations to indemnify policyholders with respect to the underlying insurance and reinsurance contracts. (q) Retroactive reinsurance contracts We record liabilities for unpaid losses and loss adjustment expenses assumed under retroactive reinsurance of short duration contracts consistent with other short duration property/casualty insurance and reinsurance contracts discussed in Note 1(p). With respect to retroactive reinsurance contracts, we also record deferred charge assets at the inception of the contracts, representing the excess, if any, of the estimated ultimate claim liabilities over the premiums earned. We subsequently amortize the deferred charge assets over the expected claim settlement periods using the interest method. Changes to the estimated timing or amount of future loss payments also produce changes in deferred charge balances. We apply changes in such estimates retrospectively and the resulting changes in deferred charge balances, together with periodic amortization, are included in insurance losses and loss adjustment expenses in the Consolidated Statements of Earnings. (r) Insurance policy acquisition costs We capitalize the incremental costs that directly relate to the successful sale of insurance contracts, subject to ultimate recoverability, and we subsequently amortize such costs to underwriting expenses as the related premiums are earned. Direct incremental acquisition costs include commissions, premium taxes and certain other costs associated with successful efforts. We expense all other underwriting costs as incurred. The recoverability of capitalized insurance policy acquisition costs generally reflects anticipation of investment income. The unamortized balances are included in other assets and were $2,658 million and $2,529 million at December 31, 2018 and 2017, respectively. (s) Life and annuity insurance benefits We compute our liabilities for insurance benefits under life contracts based upon estimated future investment yields, expected mortality, morbidity, and lapse or withdrawal rates as well as estimates of premiums we expect to receive and expenses we expect to incur in the future. These assumptions, as applicable, also include a margin for adverse deviation and may vary with the characteristics of the contract’s date of issuance, policy duration and country of risk. The interest rate assumptions used may vary by contract or jurisdiction. We discount periodic payment annuity liabilities based on the implicit rate as of the inception of the contracts such that the present value of the liabilities equals the premiums. Discount rates range from less than 1% to 7%. (t) Regulated utilities and energy businesses Certain energy subsidiaries prepare their financial statements in accordance with authoritative guidance for regulated operations, reflecting the economic effects of regulation from the ability to recover certain costs from customers and the requirement to return revenues to customers in the future through the regulated rate-setting process. Accordingly, certain costs are deferred as regulatory assets and certain income is accrued as regulatory liabilities. Regulatory assets and liabilities will be amortized into operating expenses and revenues over various future periods. Regulatory assets and liabilities are continually assessed for probable future inclusion in regulatory rates by considering factors such as applicable regulatory or legislative changes and recent rate orders received by other regulated entities. If future inclusion in regulatory rates ceases to be probable, the amount no longer probable of inclusion in regulatory rates is charged or credited to earnings (or other comprehensive income, if applicable) or returned to customers. (u) Foreign currency The accounts of our non-U.S. (v) Income taxes Berkshire files a consolidated federal income tax return in the United States, which includes eligible subsidiaries. In addition, we file income tax returns in state, local and foreign jurisdictions as applicable. Provisions for current income tax liabilities are calculated and accrued on income and expense amounts expected to be included in the income tax returns for the current year. Income taxes reported in earnings also include deferred income tax provisions. Deferred income tax assets and liabilities are computed on differences between the financial statement bases and tax bases of assets and liabilities at the enacted tax rates. Changes in deferred income tax assets and liabilities associated with components of other comprehensive income are charged or credited directly to other comprehensive income. Otherwise, changes in deferred income tax assets and liabilities are included as a component of income tax expense. The effect on deferred income tax assets and liabilities attributable to changes in enacted tax rates are charged or credited to income tax expense in the period of enactment. Valuation allowances are established for certain deferred tax assets when realization is not likely. Assets and liabilities are established for uncertain tax positions taken or positions expected to be taken in income tax returns when such positions, in our judgment, do not meet a more-likely-than-not (w) New accounting pronouncements adopted in 2018 On January 1, 2018, we adopted Accounting Standards Update (“ASU”) 2016-01 2018-02 2016-01, 2018-02 ASU 2016-01 ASU 2018-02 ASC 606 Total Increase (decrease): Assets $ — $ — $ 3,382 $ 3,382 Liabilities — — 3,453 3,453 Accumulated other comprehensive income (61,459) 84 — (61,375) Retained earnings 61,459 (84) (70) 61,305 Shareholders’ equity — — (70) (70) With respect to ASU 2016-01, after-tax In adopting ASU 2018-02, In adopting ASC 606, we recorded increases to certain assets and other liabilities, with the cumulative net effect recorded to retained earnings. Prior to January 1, 2018, we recognized revenues from the sales of fractional ownership interests in aircraft over the term of the related management services agreements, as the transfers of the ownership interests were inseparable from the management services agreements. These agreements also include provisions that require us to repurchase the fractional interest at fair market value at contract termination or upon the customer’s request following the end of a minimum commitment period. ASC 606 provides that such contracts are subject to accounting guidance for lease contracts. The principal effects of this re-characterization (x) New accounting pronouncements to be adopted subsequent to December 31, 2018 In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02 We are party to contracts where we are the lessee and other contracts where we are the lessor. For contracts where we are the lessee, our consolidated assets and liabilities increased by approximately $6 billion as of January 1, 2019, primarily due to the recognition of right-of-use In June 2016, the FASB issued ASU 2016-13 available-for-sale 2016-13 In January 2017, the FASB issued ASU 2017-04 2017-04 2017-04, 2017-04 In August 2018, the FASB issued ASU 2018-12 2018-12 2018-12

Significant business acquisitio

Significant business acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Significant business acquisitions	(2) Significant business acquisitions Our long-held acquisition strategy is to acquire businesses that have consistent earning power, good returns on equity and able and honest management. Financial results attributable to business acquisitions are included in our Consolidated Financial Statements beginning on their respective acquisition dates. In 2016, National Indemnity Company (“NICO”), a wholly-owned subsidiary, 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 closed on October 1, 2018, at which time, Medical Liability Mutual’s name was changed to MLMIC Insurance Company (“MLMIC”). As of the acquisition date, the fair value of MLMIC’s assets was approximately $6.1 billion, including cash ($230 million) and investments ($5.2 billion), and liabilities were approximately $3.6 billion, consisting primarily of unpaid losses and loss adjustment expenses ($3.2 billion). MLMIC premiums earned for the year ending December 31, 2018 were approximately $400 million. In each of the past three years, we also completed several smaller-sized “bolt-ons” bolt-on On January 29, 2016, Berkshire acquired all outstanding common stock of Precision Castparts Corp. (“PCC”) for cash of approximately $32.7 billion, which included the value of PCC shares we already owned. We funded the acquisition with a combination of existing cash balances and proceeds from a temporary credit facility. PCC is a worldwide, diversified manufacturer of complex metal components and products, serving the aerospace, power and general industrial markets. PCC also produces titanium and nickel superalloy melted and mill products for the aerospace, chemical processing, oil and gas and pollution control industries, and manufactures extruded seamless pipe, fittings and forgings for power generation and oil and gas applications. On February 29, 2016, we acquired a recapitalized Duracell Company (“Duracell”) from The Procter & Gamble Company (“P&G”) in exchange for shares of P&G common stock held by Berkshire subsidiaries, which had a fair value of approximately $4.2 billion. Duracell manufactures high-performance alkaline batteries and wireless charging technologies. Goodwill from these acquisitions is not amortizable for income tax purposes. The fair values of identified assets acquired and liabilities assumed and residual goodwill at their respective acquisition dates are summarized as follows (in millions). PCC Duracell Cash and cash equivalents $ 250 $ 1,807 Inventories 3,430 319 Property, plant and equipment 2,765 359 Goodwill 16,011 866 Other intangible assets 23,527 1,550 Other assets 1,916 242 Assets acquired $ 47,899 $ 5,143 Accounts payable, accruals and other liabilities $ 2,442 $ 410 Notes payable and other borrowings 5,251 — Income taxes, principally deferred 7,548 494 Liabilities assumed $ 15,241 $ 904 Net assets $ 32,658 $ 4,239

Investments in fixed maturity s

Investments in fixed maturity securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments in fixed maturity securities	(3) Investments in fixed maturity securities Investments in fixed maturity securities as of December 31, 2018 and 2017 are summarized by type below (in millions). Amortized Unrealized Unrealized Fair December 31, 2018 U.S. Treasury, U.S. government corporations and agencies $ 4,223 $ 22 $ (22) $ 4,223 States, municipalities and political subdivisions 182 7 — 189 Foreign governments 7,480 50 (28) 7,502 Corporate bonds 7,055 408 (23) 7,440 Mortgage-backed securities 487 59 (2) 544 $ 19,427 $ 546 $ (75) $ 19,898 December 31, 2017 U.S. Treasury, U.S. government corporations and agencies $ 3,975 $ 4 $ (26) $ 3,953 States, municipalities and political subdivisions 847 19 (12) 854 Foreign governments 8,572 274 (24) 8,822 Corporate bonds 6,279 588 (5) 6,862 Mortgage-backed securities 772 92 (2) 862 $ 20,445 $ 977 $ (69) $ 21,353 Investments in foreign governments include securities issued by national and provincial government entities as well as instruments that are unconditionally guaranteed by such entities. As of December 31, 2018, approximately 88% of our foreign government holdings were rated AA or higher by at least one of the major rating agencies. The amortized cost and estimated fair value of fixed maturity securities at December 31, 2018 are summarized below by contractual maturity dates. Amounts are in millions. Actual maturities may differ from contractual maturities due to early call or prepayment rights held by issuers. Due in one Due after one Due after five Due after Mortgage-backed Total Amortized cost $ 6,973 $ 10,937 $ 438 $ 592 $ 487 $ 19,427 Fair value 6,982 10,994 494 884 544 19,898

Investments in equity securitie

Investments in equity securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments in equity securities	(4) Investments in equity securities Investments in equity securities as of December 31, 2018 and 2017 are summarized based on the primary industry of the investee in the table below (in millions). Cost Basis Net Fair December 31, 2018 Banks, insurance and finance $ 44,332 $ 38,260 $ 82,592 Consumer products 38,783 22,838 61,621 Commercial, industrial and other 19,752 8,792 28,544 $ 102,867 $ 69,890 $ 172,757 * Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company – $14.5 billion; Apple Inc. – $40.3 billion; Bank of America Corporation – $22.6 billion; The Coca-Cola Company – $18.9 billion and Wells Fargo & Company – $20.7 billion). Cost Basis Net Unrealized Gains Fair December 31, 2017 Banks, insurance and finance $ 25,783 $ 55,026 $ 80,809 Consumer products 25,177 25,698 50,875 Commercial, industrial and other 23,716 15,140 38,856 $ 74,676 $ 95,864 $ 170,540 * Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company – $15.1 billion; Apple Inc. – $28.2 billion; Bank of America Corporation – $20.7 billion; The Coca-Cola Company – $18.4 billion and Wells Fargo & Company – $29.3 billion). In 2011, we acquired 50,000 shares of 6% Non-Cumulative

Equity method investments

Equity method investments	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity method investments	(5) Equity method investments Berkshire and its subsidiaries hold investments in certain businesses that are accounted for pursuant to the equity method. Currently, the most significant of these is our investment in the common stock of The Kraft Heinz Company (“Kraft Heinz”). Kraft Heinz is one of the world’s largest manufacturers and marketers of food and beverage products, including condiments and sauces, cheese and dairy, meals, meats, refreshment beverages, coffee and other grocery products. Berkshire currently owns 325,442,152 shares of Kraft Heinz common stock representing 26.7% of the outstanding shares. Shares of Kraft Heinz common stock are publicly-traded and the fair value of our investment at December 31, 2018 and 2017 was approximately $14.0 billion and $25.3 billion, respectively. Our carrying value of this investment at December 31, 2018 and 2017 was approximately $13.8 billion and $17.6 billion, respectively. We recorded equity method losses in 2018 of approximately $2.7 billion compared to earnings of $2.9 billion in 2017 and $923 million in 2016. Our losses in 2018 included our share of intangible asset impairment losses recorded by Kraft Heinz. In 2017, our earnings reflected our share of certain one-time Summarized unaudited financial information of Kraft Heinz follows (in millions). December 29, December 30, Assets $ 103,627 $ 120,232 Liabilities 51,721 53,985 Year ending Year ending Year ending Sales $ 26,259 $ 26,085 $ 26,335 Net earnings (losses) attributable to Kraft Heinz common shareholders $ (10,229) $ 10,999 $ 3,452 Other investments accounted for pursuant to the equity method include our investments in Berkadia Commercial Mortgage LLC (“Berkadia”), Pilot Travel Centers LLC, d/b/a Pilot Flying J (“Pilot Flying J”), and Electric Transmission Texas, LLC (“ETT”). The carrying value of our investments in these entities was approximately $3.5 billion as of December 31, 2018 and $3.4 billion as of December 31, 2017. Our equity method earnings in these entities were $563 million in 2018, $76 million in 2017 and $186 million in 2016. Additional information concerning these investments follows. We own a 50% interest in Berkadia, with Jefferies Financial Group Inc. (“Jefferies”), formerly known as Leucadia National Corporation, owning the other 50% interest. Berkadia is a servicer of commercial real estate loans in the U.S., performing primary, master and special servicing functions for U.S. government agency programs, commercial mortgage-backed securities transactions, banks, insurance companies and other financial institutions. A source of funding for Berkadia’s operations is through its issuance of commercial paper, which is currently limited to $1.5 billion. On December 31, 2018, Berkadia’s commercial paper outstanding was $1.47 billion. The commercial paper is supported by a surety policy issued by a Berkshire insurance subsidiary. Jefferies is obligated to indemnify us for one-half On October 3, 2017, we entered into an investment agreement and an equity purchase agreement whereby we acquired a 38.6% interest in Pilot Flying J, headquartered in Knoxville, Tennessee. Pilot Flying J is one of the largest operators of travel centers in North America, with more than 28,000 team members, 750 locations across the U.S. and Canada, and more than $20 billion in annual revenues. The Haslam family currently owns a 50.1% interest in Pilot Flying J and a third party owns the remaining 11.3% interest. We also entered into an agreement to acquire in 2023 an additional 41.4% interest in Pilot Flying J with the Haslam family retaining a 20% interest. As a result, Berkshire will become the majority owner of Pilot Flying J in 2023.

Investment gains_losses

Investment gains/losses	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investment gains/losses	(6) Investment gains/losses Investment gains/losses for each of the three years ending December 31, 2018 are summarized below (in millions). 2018 2017 2016 Equity securities: Unrealized investment gains/losses on securities held at the end of the period $ (22,729) $ — $ — Investment gains/losses during 2018 on securities sold in 2018 291 — — Gross realized gains — 2,237 7,853 Gross realized losses — (919) (415) (22,438) 1,318 7,438 Fixed maturity securities: Gross realized gains 480 103 58 Gross realized losses (227) (22) (51) Other 30 11 108 $ (22,155) $ 1,410 $ 7,553 Prior to 2018, we recognized investment gains and losses in earnings when we sold or otherwise disposed of equity securities based on the difference between the proceeds from the sale and the cost of the securities and also when we recognized other-than-temporary impairment losses. Beginning in 2018, equity securities gains and losses include unrealized gains and losses from changes in fair values during the period on equity securities we still own. See Note 1(w). Prior to 2018, we recorded the changes in unrealized gains and losses on our investments in equity securities in other comprehensive income. During 2018, as reflected in the Consolidated Statement of Cash Flows, we received proceeds of approximately $18.8 billion from sales of equity securities. In the preceding table, investment gains/losses on equity securities sold during 2018 reflect the difference between proceeds from sales and the fair value of the equity security sold at the beginning of the period or the purchase date, if later. Our taxable gains on equity securities sold during 2018, which are generally the difference between the proceeds from sales and our original cost, were $3.3 billion. Net gains from equity securities in 2017 included approximately $1.0 billion related to the surrender of substantially all of our BAC Preferred as described in Note 4. Gross gains from equity securities in 2016 included approximately $4.2 billion from the redemptions of our investments in Wm. Wrigley Jr. Company and Kraft Heinz preferred stock and from the sale of Dow Chemical Company common stock received in the conversion of our Dow Chemical preferred stock investment. In 2016, we also recorded a non-cash

Loans and finance receivables

Loans and finance receivables	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans and finance receivables	(7) Loans and finance receivables Loans and finance receivables are summarized as follows (in millions). December 31, 2018 2017 Loans and finance receivables before allowances and discounts $ 16,622 $ 14,126 Allowances for uncollectible loans (177 ) (180 ) Unamortized acquisition discounts (165 ) (198 ) $ 16,280 $ 13,748 Loans and finance receivables are predominantly installment loans originated or acquired by our manufactured housing business. Provisions for loan losses for 2018 and 2017 were $141 million and $160 million, respectively. Loan charge-offs, net of recoveries, were $144 million in 2018 and $162 million in 2017. At December 31, 2018, approximately 98% of the manufactured housing loan balances were evaluated collectively for impairment, with the remainder evaluated individually. As part of the evaluation process, credit quality indicators are reviewed and loans are designated as performing or non-performing. Additionally, during 2018, an insurance subsidiary entered into an agreement with Seritage Growth Properties to provide a $2.0 billion term loan facility, which matures on July 31, 2023. As of December 31, 2018, the outstanding loans under the facility were approximately $1.6 billion.

Other receivables

Other receivables	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Other receivables	(8) Other receivables Other receivables of insurance and other businesses are comprised of the following (in millions). December 31, 2018 2017 Insurance premiums receivable $ 12,452 $ 11,058 Reinsurance recoverable on unpaid losses 3,060 3,201 Trade receivables 12,617 12,031 Other 3,823 3,464 Allowances for uncollectible accounts (388 ) (362 ) $ 31,564 $ 29,392 Receivables of our railroad and our utilities and energy businesses are comprised of the following (in millions). December 31, 2018 2017 Trade receivables $ 3,433 $ 3,346 Other 362 313 Allowances for uncollectible accounts (129 ) (128 ) $ 3,666 $ 3,531 Trade receivables include unbilled revenue of $554 million and $665 million as of December 31, 2018 and 2017, respectively, attributable to the regulated utility businesses.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventories	(9) Inventories Inventories are comprised of the following (in millions). December 31, 2018 2017 Raw materials $ 4,182 $ 3,479 Work in process and other 2,625 2,568 Finished manufactured goods 4,541 4,505 Goods acquired for resale 7,721 6,814 $ 19,069 $ 17,366

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2018
Property, plant and equipment	(10) Property, plant and equipment A summary of property, plant and equipment of our insurance and other businesses follows (in millions). December 31, 2018 2017 Land $ 2,536 $ 2,523 Buildings and improvements 9,959 9,409 Machinery and equipment 22,574 21,190 Furniture, fixtures and other 4,758 4,519 39,827 37,641 Accumulated depreciation (19,199 ) (17,773 ) $ 20,628 $ 19,868 A summary of property, plant and equipment of our railroad and our utilities and energy businesses follows (in millions). The utility generation, transmission and distribution systems and interstate natural gas pipeline assets are owned by regulated public utility and natural gas pipeline subsidiaries. December 31, 2018 2017 Railroad: Land, track structure and other roadway $ 59,509 $ 57,408 Locomotives, freight cars and other equipment 13,016 12,543 Construction in progress 664 989 73,189 70,940 Accumulated depreciation (10,004 ) (8,627 ) 63,185 62,313 Utilities and energy: Utility generation, transmission and distribution systems 77,288 74,660 Interstate natural gas pipeline assets 7,524 7,176 Independent power plants and other assets 8,324 7,499 Construction in progress 3,110 2,556 96,246 91,891 Accumulated depreciation (27,651 ) (26,020 ) 68,595 65,871 $ 131,780 $ 128,184 Depreciation expense for each of the three years ending December 31, 2018 is summarized below (in millions). 2018 2017 2016 Insurance and other $ 2,186 $ 2,116 $ 2,017 Railroad, utilities and energy 5,098 4,852 4,639 $ 7,284 $ 6,968 $ 6,656
Equipment held for lease [Member]
Property, plant and equipment	(11) Equipment held for lease Equipment held for lease is summarized below (in millions). Equipment held for lease includes railcars, aircraft, over-the-road December 31, 2018 2017 Railcars $ 8,862 $ 8,352 Aircraft 7,376 1,456 Other equipment held for lease 4,379 3,967 20,617 13,775 Accumulated depreciation (6,319 ) (3,608) $ 14,298 $ 10,167 Depreciation expense for equipment held for lease was $1,102 million in 2018, $751 million in 2017 and $755 million in 2016. As of December 31, 2018, the minimum future lease rentals to be received on equipment held for lease were as follows (in millions): 2019 – $2,493; 2020 – $1,771; 2021 – $1,222; 2022 – $779; 2023 – $421; and thereafter – $377.

Goodwill and other intangible a

Goodwill and other intangible assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and other intangible assets	(12) Goodwill and other intangible assets Reconciliations of the changes in the carrying value of goodwill during 2018 and 2017 follows (in millions). December 31, 2018 2017 Balance at beginning of year $ 81,258 $ 79,486 Acquisitions of businesses 376 1,545 Other, including foreign currency translation (609 ) 227 Balance at end of year $ 81,025 $ 81,258 Our other intangible assets and related accumulated amortization are summarized as follows (in millions). December 31, 2018 December 31, 2017 Gross carrying Accumulated Gross carrying Accumulated Insurance and other $ 40,493 $ 8,994 $ 40,225 $ 7,707 Railroad, utilities and energy 1,011 362 988 324 $ 41,504 $ 9,356 $ 41,213 $ 8,031 Trademarks and trade names $ 5,368 $ 750 $ 5,381 $ 692 Patents and technology 4,446 2,790 4,341 2,493 Customer relationships 28,375 4,573 28,322 3,722 Other 3,315 1,243 3,169 1,124 $ 41,504 $ 9,356 $ 41,213 $ 8,031 Intangible asset amortization expense was $1,393 million in 2018, $1,469 million in 2017 and $1,490 million in 2016. Estimated amortization expense over the next five years is as follows (in millions): 2019 – $1,318; 2020 – $1,224; 2021 – $1,136; 2022 – $1,063 and 2023 – $1,018. Intangible assets with indefinite lives as of December 31, 2018 and 2017 were $18.9 billion and primarily related to certain customer relationships and trademarks and trade names.

Derivative contracts

Derivative contracts	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative contracts	(13) Derivative contracts We are party to derivative contracts through certain of our subsidiaries. Currently, the most significant derivative contracts consist of equity index put option contracts. The liabilities and related notional values of these contracts follows (in millions). Liabilities Notional December 31, 2018 $ 2,452 $ 26,759 December 31, 2017 2,172 28,753 Notional value represents the aggregate undiscounted amounts payable assuming that the value of each index is zero at each contract’s expiration date. Certain of these contracts are denominated in foreign currencies. Notional amounts are based on the foreign currency exchange rates as of each balance sheet date. We recorded derivative contract losses of $300 million in 2018 and gains of $718 million in 2017, with respect to our equity index put option contracts. The losses in 2018 were primarily due to decreases in equity index values during the fourth quarter. Derivative contract gains in 2016 were $751 million, which included $662 million related to equity index put option contracts and $89 million related to a credit default contract that was terminated. The equity index put option contracts are European style options written prior to March 2008 on four major equity indexes. The remaining contracts expire between April 2019 and October 2025. At December 31, 2018, the remaining weighted average life of all contracts was approximately 1.9 years. In 2018, one equity index put option contract expired and another contract was terminated by mutual agreement with the counterparty. These contracts had an aggregate notional value of approximately $1.2 billion. Contracts with notional values of $12.2 billion will expire in 2019. Future payments, if any, under any given contract will be required if the prevailing index value is below the contract strike price at the expiration date. We received aggregate premiums of $4.0 billion on the remaining contracts at the contract inception dates and we have no counterparty credit risk. The aggregate intrinsic value (the undiscounted liability assuming the contracts are settled based on the index values and foreign currency exchange rates as of the balance sheet date) was $1,653 million at December 31, 2018 and $789 million at December 31, 2017. These contracts may not be unilaterally terminated or fully settled before the expiration dates and the ultimate amount of cash basis gains or losses on these contracts will not be determined until the contract expiration dates. A limited number of our equity index put option contracts contain collateral posting requirements with respect to changes in the fair value or intrinsic value of the contracts and/or a downgrade of Berkshire’s credit ratings. As of December 31, 2018, we did not have any collateral posting requirements. If Berkshire’s credit ratings (currently AA from Standard & Poor’s and Aa2 from Moody’s) are downgraded below either A- Our regulated utility subsidiaries are exposed to variations in the prices of fuel required to generate electricity, wholesale electricity purchased and sold and natural gas supplied for customers. We may use forward purchases and sales, futures, swaps and options to manage a portion of these price risks. Most of the net derivative contract assets or liabilities of our regulated utilities are probable of recovery through rates and are offset by regulatory liabilities or assets. Derivative contract assets are included in other assets and were $172 million as of December 31, 2018 and $142 million as of December 31, 2017. Derivative contract liabilities are included in accounts payable, accruals and other liabilities and were $111 million as of December 31, 2018 and $82 million as of December 31, 2017.

Supplemental cash flow informat

Supplemental cash flow information	12 Months Ended
	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental cash flow information	(14) Supplemental cash flow information A summary of supplemental cash flow information for each of the three years ending December 31, 2018 is presented in the following table (in millions). 2018 2017 2016 Cash paid during the period for: Income taxes $ 4,354 $ 3,286 $ 4,719 Interest: Insurance and other 1,111 1,260 944 Railroad, utilities and energy 2,867 2,828 2,788 Non-cash Liabilities assumed in connection with business acquisitions 3,735 747 16,555 Equity securities exchanged in connection with business acquisitions — — 4,239 Conversions and other exchanges of investments — — 4,154 Equity securities surrendered in connection with warrant exercise — 4,965 —

Unpaid losses and loss adjustme

Unpaid losses and loss adjustment expenses	12 Months Ended
	Dec. 31, 2018
Insurance [Abstract]
Unpaid losses and loss adjustment expenses	(15) Unpaid losses and loss adjustment expenses Our liabilities for unpaid losses and loss adjustment expenses (also referred to as “claim liabilities”) under short duration property and casualty insurance and reinsurance contracts are based upon estimates of the ultimate claim costs associated with claim occurrences as of the balance sheet date and include estimates for incurred-but-not-reported 2018 2017 2016 Balances – beginning of year: Gross liabilities $ 61,122 $ 53,379 $ 50,519 Reinsurance recoverable on unpaid losses (3,201 ) (3,338 ) (3,307 ) Net liabilities 57,921 50,041 47,212 Incurred losses and loss adjustment expenses: Current accident year events 39,876 37,702 30,636 Prior accident years’ events (1,406 ) (544 ) (1,443 ) Total incurred losses and loss adjustment expenses 38,470 37,158 29,193 Paid losses and loss adjustment expenses: Current accident year events (18,391 ) (17,425 ) (14,898 ) Prior accident years’ events (15,452 ) (12,507 ) (10,929 ) Total payments (33,843 ) (29,932 ) (25,827 ) Foreign currency translation adjustment (331 ) 654 (537 ) Business acquisition 3,181 — — Balances – end of year: Net liabilities 65,398 57,921 50,041 Reinsurance recoverable on unpaid losses 3,060 3,201 3,338 Gross liabilities $ 68,458 $ 61,122 $ 53,379 Incurred losses and loss adjustment expenses in the preceding table were recorded in earnings in each period and related to insured events occurring in the current year (“current accident year”) and events occurring in all prior years (“prior accident years”). Current accident year losses in 2018 included $1.6 billion from four significant catastrophe events, while current accident year losses in 2017 included approximately $3 billion from six significant catastrophe events during that year. As discussed in Note 2, NICO acquired MLMIC, a writer of medical professional liability insurance, on October 1, 2018. Incurred losses and loss adjustment expenses from the net reductions of estimated ultimate liabilities for prior accident years were $1,406 million in 2018, $544 million in 2017 and $1,443 million in 2016. These reductions, as percentages of the net liabilities at the beginning of each year, were 2.4% in 2018, 1.1% in 2017 and 3.1% in 2016. Estimated ultimate liabilities for prior years’ loss events related to primary insurance were decreased $937 million in 2018, $249 million in 2017 and $569 million in 2016. These decreases were primarily attributable to lower than anticipated medical malpractice and workers’ compensation losses. Liabilities for prior years’ private passenger auto claims were also reduced in 2018 and 2016, but were increased in 2017. Estimated ultimate liabilities for prior years’ loss events related to property and casualty reinsurance were reduced $469 million in 2018, $295 million in 2017 and $874 million in 2016. The decrease in 2017 was net of increased losses from a United Kingdom government-mandated change to the computation of certain personal injury lump sum settlements and higher than expected property losses. Estimated claim liabilities for environmental, asbestos and other latent injury exposures, net of reinsurance recoverable, were approximately $1.7 billion at December 31, 2018 and $1.6 billion at December 31, 2017. These liabilities are subject to change due to changes in the legal and regulatory environment as described in Note 16. We are unable to reliably estimate additional losses or a range of losses that are reasonably possible for these claims. A reconciliation of the disaggregated net unpaid losses and allocated loss adjustment expenses (the latter referred to as “ALAE”) of GEICO, Berkshire Hathaway Reinsurance Group (“BHRG”) and Berkshire Hathaway Primary Group (“BH Primary”) to our consolidated unpaid losses and loss adjustment expenses as of December 31, 2018, follows (in millions). GEICO BHRG BHRG BH Primary BH Primary Total Unpaid losses and ALAE, net $ 17,318 $ 9,395 $ 19,966 $ 7,288 $ 8,694 $ 62,661 Reinsurance recoverable 896 312 850 53 940 3,051 Unpaid unallocated loss adjustment expenses 2,015 Other unpaid losses and loss adjustment expenses 731 Unpaid losses and loss adjustment expenses $ 68,458 GEICO GEICO’s claim liabilities predominantly relate to various types of private passenger auto liability and physical damage claims. For such claims, we establish and evaluate unpaid claim liabilities using standard actuarial loss development methods and techniques. The actuarial methods utilize historical claims data, adjusted when deemed appropriate to reflect perceived changes in loss patterns. Claim liabilities include average, case, case development and IBNR estimates. We establish average liabilities based on expected severities for newly reported physical damage and liability claims prior to establishing an individual case reserve when we have insufficient time or information to make specific claim estimates and for a large number of minor physical damage claims that once reported are quickly settled. We establish liability case loss estimates, which includes loss adjustment expenses, once the facts and merits of the claim are evaluated. Estimates for liability coverages are more uncertain primarily due to the longer claim-tails, the greater chance of protracted litigation and the incompleteness of facts at the time the case estimate is first established. The “claim-tail” is the time period between the claim occurrence date and settlement date. Consequently, we establish additional case development liabilities, which are usually percentages of the case liabilities. For unreported claims, IBNR liabilities are estimated by projecting the ultimate number of claims expected (reported and unreported) for each significant coverage and deducting reported claims to produce estimated unreported claims. The product of the average cost per unreported claim and the number of unreported claims produces the IBNR liability estimate. We may record supplemental IBNR liabilities in certain situations when actuarial techniques are difficult to apply. GEICO’s incurred and paid losses and ALAE, net of reinsurance, are summarized by accident year below. IBNR and case development liabilities are as of December 31, 2018. Claim counts are established when accidents that may result in a liability are reported and are based on policy coverage. Each claim event may generate claims under multiple coverages, and thus may result in multiple counts. The “Cumulative Number of Reported Claims” includes the combined number of reported claims for all policy coverages and excludes projected IBNR claims. Dollars are in millions. Accident Year Incurred Losses and ALAE through December 31, IBNR and Case Cumulative 2014* 2015* 2016* 2017* 2018 2014 $ 14,680 $ 14,572 $ 14,559 $ 14,589 $ 14,651 $ 148 7,976 2015 16,887 16,875 16,993 17,039 319 8,926 2016 19,106 19,390 19,364 823 9,633 2017 22,675 22,257 2,208 10,816 2018 24,120 4,659 10,968 Incurred losses and ALAE $ 97,431 Accident Year Cumulative Paid Losses and ALAE through December 31, 2014* 2015* 2016* 2017* 2018 2014 $ 9,199 $ 12,036 $ 13,140 $ 13,850 $ 14,273 2015 10,606 13,858 15,285 16,186 2016 12,020 15,862 17,493 2017 13,878 18,249 2018 14,498 Paid losses and ALAE 80,699 Net unpaid losses and ALAE for 2014 – 2018 accident years 16,732 Net unpaid losses and ALAE for accident years before 2014 586 Net unpaid losses and ALAE $ 17,318 * Unaudited supplemental information BHRG We use a variety of actuarial methodologies to establish BHRG’s property and casualty claims liabilities. We use certain methodologies, such as paid and incurred loss development techniques, incurred and paid loss Bornhuetter-Ferguson techniques and frequency and severity techniques, as well as ground-up Our claims liabilities are principally a function of reported losses from ceding companies, case development and IBNR liability estimates. Case loss estimates are reported under our contracts either individually or in bulk as provided under the terms of the contracts. We may independently evaluate case losses reported by the ceding company, and if deemed appropriate, we may establish case liabilities based on our estimates. Estimated IBNR liabilities are driven by expected case loss emergence patterns and expected loss ratios, which may be evaluated as groups or portfolios of contracts with similar exposures, or on an individual contract-by-contract per-contract Incurred and paid losses and ALAE of BHRG are disaggregated based on losses that are expected to have shorter claim-tails (property) and losses expected to have longer claim-tails (casualty). Under certain contracts, the coverage can apply to multiple lines of business written by the ceding company, whether property, casualty or combined, and the ceding company may not report loss data by such lines consistently, if at all. In those instances, we allocated losses to property and casualty coverages based on internal estimates. BHRG’s disaggregated incurred and paid losses and ALAE are summarized by accident year, net of reinsurance. IBNR and case development liabilities are as of December 31, 2018. Dollars are in millions. BHRG Property Accident Year Incurred Losses and ALAE through December 31, IBNR and Case 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 2,366 $ 2,037 $ 2,232 $ 2,154 $ 2,058 $ 2,031 $ 1,990 $ 1,985 $1,984 $ 1,984 $ 7 2010 2,523 2,380 2,408 2,274 2,180 2,145 2,126 2,106 2,114 23 2011 4,300 4,084 3,810 3,720 3,719 3,689 3,666 3,652 52 2012 3,144 2,833 2,629 2,389 2,336 2,333 2,315 65 2013 3,196 3,039 2,695 2,604 2,584 2,524 105 2014 2,621 2,427 2,315 2,171 2,115 120 2015 3,244 3,088 2,531 2,938 136 2016 3,267 3,906 3,625 583 2017 5,248 4,958 600 2018 4,373 2,125 Incurred losses and ALAE $ 30,598 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 402 $ 1,110 $ 1,613 $ 1,777 $ 1,846 $ 1,916 $ 1,950 $ 1,959 $ 1,961 $ 1,963 2010 336 1,024 1,506 1,772 1,931 1,987 2,033 2,058 2,065 2011 701 2,282 2,931 3,200 3,310 3,398 3,440 3,485 2012 266 1,222 1,801 1,939 2,028 2,103 2,123 2013 516 1,427 1,866 2,063 2,184 2,264 2014 465 1,244 1,569 1,708 1,773 2015 569 1,590 1,940 2,135 2016 703 1,792 2,187 2017 1,026 2,713 2018 910 Paid losses and ALAE 21,618 Net unpaid losses and ALAE for 2009 – 2018 accident years 8,980 Net unpaid losses and ALAE for accident years before 2009 415 Net unpaid losses and ALAE $ 9,395 * Unaudited supplemental information BHRG Casualty Accident Year Incurred Losses and ALAE through December 31, IBNR and Case 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 2,375 $2,687 $ 2,546 $ 2,476 $ 2,414 $ 2,339 $ 2,292 $ 2,231 $2,192 $ 2,209 $ 213 2010 2,301 2,387 2,322 2,258 2,139 2,090 2,044 1,883 1,963 228 2011 2,609 2,696 2,567 2,508 2,418 2,327 2,320 2,282 363 2012 2,789 2,964 2,799 2,864 2,793 2,682 2,615 514 2013 2,130 2,259 2,290 2,134 2,082 2,028 544 2014 1,867 2,061 2,029 1,991 1,905 611 2015 1,875 2,072 2,099 2,000 647 2016 1,903 2,107 2,014 818 2017 2,189 2,676 1,141 2018 2,917 1,856 Incurred losses and ALAE $ 22,609 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 247 $ 852 $ 940 $ 1,211 $ 1,430 $ 1,586 $ 1,622 $ 1,658 $1,684 $ 1,716 2010 118 546 838 1,026 1,278 1,374 1,437 1,482 1,531 2011 292 817 1,160 1,400 1,489 1,581 1,659 1,698 2012 309 749 1,140 1,370 1,527 1,651 1,750 2013 291 521 807 935 1,039 1,140 2014 150 478 644 753 875 2015 196 491 714 834 2016 253 556 734 2017 231 568 2018 267 Paid losses and ALAE 11,113 Net unpaid losses and ALAE for 2009 – 2018 accident years 11,496 Net unpaid losses and ALAE for accident years before 2009 8,470 Net unpaid losses and ALAE $ 19,966 * Unaudited supplemental information BH Primary BH Primary’s liabilities for unpaid losses and loss adjustment expenses primarily derive from medical professional liability and workers’ compensation and other casualty insurance, including commercial auto and general liability insurance. Incurred and paid losses and ALAE are summarized by accident year in the following tables, disaggregated by medical professional liability and workers’ compensation and other casualty coverages. IBNR and case development liabilities are as of December 31, 2018. The cumulative number of reported claims reflects the number of individual claimants, and includes claims that ultimately result in no liability or payment. Dollars are in millions. BH Primary Medical Professional Liability We estimate the ultimate expected incurred losses and loss adjustment expenses for medical professional claim liabilities using commonly accepted actuarial methodologies such as the paid and incurred development method, Bornhuetter-Ferguson based methods, hindsight outstanding severity method, trended severity method and trended pure premium method. Using a combination of these methodologies produces a range of loss estimates from which we determine our best estimate. Periodically, we study developments in older accident years and adjust initial loss estimates to reflect recent development based upon claim age, coverage and litigation experience. As previously noted, MLMIC was acquired on October 1, 2018. MLMIC’s incurred and paid losses and ALAE are included for all years presented retrospectively. Accident Year Incurred Losses and ALAE through December 31, IBNR and Cumulative 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 1,423 $ 1,349 $ 1,294 $ 1,251 $ 1,153 $ 1,060 $ 988 $ 941 $ 922 $ 904 $ 22 13 2010 1,399 1,346 1,348 1,329 1,234 1,140 1,085 1,031 1,006 43 13 2011 1,346 1,334 1,321 1,262 1,173 1,115 1,050 1,004 71 13 2012 1,336 1,306 1,277 1,223 1,168 1,078 1,035 108 13 2013 1,328 1,296 1,261 1,195 1,127 1,086 160 12 2014 1,370 1,375 1,305 1,246 1,218 296 13 2015 1,374 1,342 1,269 1,290 450 14 2016 1,392 1,416 1,414 641 14 2017 1,466 1,499 1,011 18 2018 1,602 1,410 15 Incurred losses and ALAE $ 12,058 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 5 $ 90 $ 203 $ 350 $ 480 $ 619 $ 699 $ 753 $ 789 $ 810 2010 15 95 224 377 526 654 745 810 853 2011 16 82 200 356 517 632 711 767 2012 15 93 218 377 522 642 725 2013 15 90 219 368 518 635 2014 21 106 238 396 540 2015 23 108 218 382 2016 22 115 274 2017 27 128 2018 35 Paid losses and ALAE 5,149 Net unpaid losses and ALAE for 2009 – 2018 accident years 6,909 Net unpaid losses and ALAE for accident years before 2009 379 Net unpaid losses and ALAE $ 7,288 * Unaudited supplemental information BH Primary Workers’ Compensation and Other Casualty We periodically evaluate ultimate loss and loss adjustment expense estimates for the workers’ compensation and other casualty claims using a combination of commonly accepted actuarial methodologies such as the Bornhuetter-Ferguson and chain-ladder approaches using paid and incurred loss data. Paid and incurred loss data is segregated and analyzed by state due to the different state regulatory frameworks that may impact certain factors including the duration and amount of loss payments. We also separately study the various components of liabilities, such employee lost wages, medical expenses and the costs of claims investigations and administration. We establish case liabilities for reported claims based upon the facts and circumstances of the claim. The excess of the ultimate projected losses, including the expected development of case estimates, and the case-basis liabilities is included in IBNR liabilities. Accident Year Incurred Losses and ALAE through December 31, IBNR and Cumulative 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 732 $ 673 $ 676 $ 632 $ 609 $ 595 $ 589 $ 585 $ 576 $ 562 $ 40 46 2010 715 675 644 609 589 584 576 562 553 42 47 2011 786 706 709 657 653 647 632 622 72 51 2012 907 887 876 828 815 792 779 105 63 2013 1,339 1,310 1,257 1,210 1,173 1,148 188 83 2014 1,866 1,737 1,716 1,641 1,572 287 112 2015 2,314 2,244 2,156 2,124 445 133 2016 2,656 2,561 2,475 833 127 2017 3,262 3,122 1,395 143 2018 3,761 2,459 142 Incurred losses and ALAE $ 16,718 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 99 $ 228 $ 328 $ 389 $ 434 $ 464 $ 488 $ 499 $ 503 $ 507 2010 106 250 327 393 437 465 479 484 491 2011 114 222 344 415 470 498 512 522 2012 101 301 422 515 576 607 627 2013 193 452 650 776 842 887 2014 247 581 837 1,046 1,155 2015 297 715 1,044 1,328 2016 332 792 1,181 2017 467 1,078 2018 570 Paid losses and ALAE 8,346 Net unpaid losses and ALAE for 2009 – 2018 accident years 8,372 Net unpaid losses and ALAE for accident years before 2009 322 Net unpaid losses and ALAE $ 8,694 * Unaudited supplemental information Supplemental unaudited average historical claims duration information based on the net losses and ALAE incurred and paid accident year data in the preceding tables follows. The percentages show the average portions of net losses and ALAE paid by each succeeding year, with year 1 representing the current accident year. Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance In Year 1 2 3 4 5 6 7 8 9 10 GEICO 61.7% 19.6% 8.1% 4.9% 2.8% BHRG Property 19.0% 36.1% 18.3% 7.9% 4.3% 3.0% 1.5% 1.0% 0.2% 0.1% BHRG Casualty 10.4% 17.8% 11.5% 8.5% 7.4% 5.1% 3.0% 1.9% 1.8% 1.4% BH Primary Medical Professional Liability 1.6% 7.3% 11.5% 14.5% 14.1% 12.4% 8.4% 6.0% 4.1% 2.3% BH Primary Workers’ Compensation and Other Casualty 15.8% 21.5% 16.5% 12.0% 7.6% 4.6% 2.9% 1.5% 1.0% 0.7%

Retroactive reinsurance contrac

Retroactive reinsurance contracts	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Retroactive reinsurance contracts	(16) Retroactive reinsurance contracts Retroactive reinsurance policies provide indemnification of losses and loss adjustment expenses of short-duration insurance contracts with respect to underlying loss events that occurred prior to the contract inception date. Claims payments may commence immediately after the contract date or, if applicable, once a contractual retention amount has been reached. Reconciliations of the changes in estimated liabilities for retroactive reinsurance unpaid losses and loss adjustment expenses (“claim liabilities”) and related deferred charge reinsurance assumed assets for each of the three years ended December 31, 2018 follows (in millions). 2018 2017 2016 Unpaid losses Deferred Unpaid losses Deferred Unpaid losses Deferred Balances – beginning of year $ 42,937 $ (15,278) $ 24,972 $ (8,047) $ 24,058 $ (7,687) Incurred losses and loss adjustment expenses Current year contracts 603 (86) 19,005 (7,730) 2,136 (874) Prior years’ contracts (341) 1,260 (41) 499 (63) 514 Total 262 1,174 18,964 (7,231) 2,073 (360) Paid losses and loss adjustment expenses (1,365) — (999) — (1,159) — Balances – end of year $ 41,834 $ (14,104) $ 42,937 $ (15,278) $ 24,972 $ (8,047) Incurred losses and loss adjustment expenses, net of deferred charges $ 1,436 $ 11,733 $ 1,713 In the preceding table, classifications of incurred losses and loss adjustment expenses are based on the inception dates of the contracts. We do not believe that analysis of losses incurred and paid by accident year of the underlying event is relevant or meaningful given that our exposure to losses incepts when the contract incepts. Further, we believe the classifications of reported claims and case development liabilities has little or no practical analytical value. In 2017, NICO entered into an agreement with various subsidiaries of American International Group, Inc. (collectively, “AIG”), which became effective on February 2, 2017. Under this agreement, NICO agreed to indemnify AIG for 80% of up to $25 billion of losses and allocated loss adjustment expenses in excess of $25 billion retained by AIG, with respect to certain commercial insurance loss events occurring prior to 2016. As of the effective date, we recorded premiums earned of $10.2 billion, and we also recorded a liability for unpaid losses and loss adjustment expenses of $16.4 billion and a deferred charge reinsurance assumed asset of $6.2 billion. Berkshire agreed to guarantee the timely payment of all amounts due to AIG under the agreement. In the fourth quarter of 2017, we increased our estimated ultimate claim liabilities under the aforementioned AIG contract by approximately $1.8 billion based on higher than expected loss payments reported by AIG under the contractual retention. We also increased the related deferred charge asset by $1.7 billion based on our re-estimation Incurred losses and loss adjustment expenses related to contracts written in prior years were $919 million in 2018, $458 million in 2017 and $451 million in 2016, which included recurring amortization of deferred charges and the effect of changes in the timing and amount of expected future loss payments. In establishing retroactive reinsurance claim liabilities, we analyze historical aggregate loss payment patterns and project losses into the future under various probability-weighted scenarios. We expect the claim-tail to be very long for many contracts, with some lasting several decades. We monitor claim payment activity and review ceding company reports and other information concerning the underlying losses. We reassess and revise the expected timing and amounts of ultimate losses periodically or when significant events are revealed through our monitoring and review processes. Our retroactive reinsurance claim liabilities include estimated liabilities for environmental, asbestos and other latent injury exposures of approximately $13.1 billion at December 31, 2018 and $14.0 billion at December 31, 2017. Retroactive reinsurance contracts are generally subject to aggregate policy limits and thus, our exposure to such claims under these contracts is likewise limited. We monitor evolving case law and its effect on environmental and other latent injury claims. Changing government regulations, newly identified toxins, newly reported claims, new theories of liability, new contract interpretations and other factors could result in increases in these liabilities, which could be material to our results of operations. We are unable to reliably estimate the amount of additional net loss or the range of net loss that is reasonably possible.

Notes payable and other borrowi

Notes payable and other borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Notes payable and other borrowings	(17) Notes payable and other borrowings Notes payable and other borrowings are summarized below (in millions). The weighted average interest rates and maturity date ranges shown in the following tables are based on borrowings as of December 31, 2018. Weighted December 31, 2018 2017 Insurance and other: Berkshire Hathaway Inc. (“Berkshire”): U.S. Dollar denominated borrowings due 2019-2047 3.1% $ 9,065 $ 10,603 Euro denominated borrowings due 2020-2035 1.1% 7,806 8,164 Berkshire Hathaway Finance Corporation (“BHFC”) due 2019-2048 3.4% 10,650 12,926 Subsidiary borrowings due 2019-2045 4.0% 5,597 6,884 Short-term subsidiary borrowings 4.3% 1,857 1,832 $ 34,975 $ 40,409 The carrying value of Berkshire’s Euro denominated senior notes reflects the Euro/U.S. Dollar exchange rate as of the balance sheet date. The gains or losses arising from the changes in the Euro/U.S. Dollar exchange rate during the period are recorded in earnings as a component of selling, general and administrative expenses. Changes in the Euro/U.S. Dollar exchange rate resulted in pre-tax Borrowings of BHFC, a wholly owned finance subsidiary of Berkshire, consist of senior unsecured notes used to fund manufactured housing loans originated or acquired and equipment held for lease of certain finance subsidiaries. In August 2018, BHFC issued $2.35 billion of 4.2% senior notes due in 2048. During 2018, BHFC repaid $4.6 billion of maturing senior notes. During January 2019, BHFC issued $1.25 billion of 4.25% senior notes due in 2049 and repaid $950 million of maturing notes. Such borrowings are fully and unconditionally guaranteed by Berkshire. In addition to BHFC’s borrowings, Berkshire guaranteed approximately $1.7 billion of other subsidiary borrowings at December 31, 2018. Generally, Berkshire’s guarantee of a subsidiary’s debt obligation is an absolute, unconditional and irrevocable guarantee for the full and prompt payment when due of all payment obligations. Weighted December 31, 2018 2017 Railroad, utilities and energy: Berkshire Hathaway Energy Company (“BHE”) and subsidiaries: BHE senior unsecured debt due 2020-2049 4.6 % $ 8,577 $ 6,452 Subsidiary and other debt due 2019-2064 4.7 % 28,196 28,739 Short-term debt 3.1 % 2,516 4,488 Burlington Northern Santa Fe and subsidiaries due 2019-2097 4.7 % 23,226 22,499 $ 62,515 $ 62,178 BHE subsidiary debt represents amounts issued pursuant to separate financing agreements. Substantially all of the assets of certain BHE subsidiaries are, or may be, pledged or encumbered to support or otherwise secure debt. These borrowing arrangements generally contain various covenants, including covenants which pertain to leverage ratios, interest coverage ratios and/or debt service coverage ratios. During 2018, BHE and its subsidiaries issued approximately $5.5 billion of long-term debt. The debt issued in 2018 has maturity dates ranging from 2020 to 2049 and a weighted average interest rate of 3.6%. Proceeds from these debt issuances were used to repay debt, to fund capital expenditures and for general corporate purposes. BNSF’s borrowings are primarily senior unsecured debentures. In 2018, BNSF issued $1.5 billion of senior unsecured debentures due in 2048. These debentures have a weighted average interest rate of 4.1%. As of December 31, 2018, BNSF, BHE and their subsidiaries were in compliance with all applicable debt covenants. Berkshire does not guarantee any debt, borrowings or lines of credit of BNSF, BHE or their subsidiaries. As of December 31, 2018, our subsidiaries had unused lines of credit and commercial paper capacity aggregating approximately $7.3 billion to support short-term borrowing programs and provide additional liquidity. Such unused lines of credit included approximately $6.1 billion related to BHE and its subsidiaries. Debt principal repayments expected during each of the next five years are as follows (in millions). 2019 2020 2021 2022 2023 Insurance and other $ 6,760 $ 2,811 $ 3,261 $ 1,616 $ 5,371 Railroad, utilities and energy 5,452 2,778 2,260 3,346 4,066 $ 12,212 $ 5,589 $ 5,521 $ 4,962 $ 9,437

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes	(18) Income taxes The liabilities for income taxes reflected in our Consolidated Balance Sheets are as follows (in millions). December 31, 2018 2017 Currently payable (receivable) $ 323 $ (129) Deferred 50,503 56,182 Other 549 554 $ 51,375 $ 56,607 On December 22, 2017, President Trump signed into law legislation known as the Tax Cuts and Jobs Act of 2017 (“TCJA”). Among its provisions, the TCJA reduced the statutory U.S. Corporate income tax rate from 35% to 21% effective January 1, 2018. The TCJA also included a one-time Upon the enactment of the TCJA, we recorded a reduction in our deferred income tax liabilities of approximately $35.6 billion for the effect of the aforementioned change in the U.S. statutory income tax rate. As a result, we recorded an income tax benefit of approximately $29.6 billion and we increased regulatory liabilities of our regulated utility subsidiaries by approximately $6.0 billion for the portion of the deferred income tax liability reduction that we will be required to, effectively, refund to customers in the rate setting process. We also recognized an income tax charge of approximately $1.4 billion with respect to the deemed repatriation of the accumulated undistributed post-1986 earnings of our foreign subsidiaries. Thus, upon the enactment of the TCJA, we included a net income tax benefit in our 2017 earnings of approximately $28.2 billion. In 2018, we reduced our estimate of the income taxes on the deemed repatriation of earnings of foreign subsidiaries by $141 million and recognized additional deferred income tax rate change effects. We have not established deferred income taxes on accumulated undistributed earnings of certain foreign subsidiaries, which are expected to be reinvested indefinitely. Repatriation of all accumulated earnings of foreign subsidiaries would be impracticable to the extent that such earnings represent capital to support normal business operations. Generally, no U.S. federal income taxes will be imposed on future distributions of foreign earnings under the current law. However, distributions to the U.S. or other foreign jurisdictions could be subject to withholding and other local taxes. The tax effects of temporary differences that give rise to significant portions of deferred tax assets and deferred tax liabilities are shown below (in millions). December 31, 2018 2017 Deferred tax liabilities: Investments – unrealized appreciation and cost basis differences $ 17,765 $ 24,251 Deferred charges reinsurance assumed 2,970 3,226 Property, plant and equipment 28,279 26,671 Goodwill and other intangible assets 7,199 7,204 Other 3,187 3,216 59,400 64,568 Deferred tax assets: Unpaid losses and loss adjustment expenses (1,238) (1,231) Unearned premiums (767) (345) Accrued liabilities (1,956) (2,501) Regulatory liabilities (1,673) (1,707) Other (3,263) (2,602) (8,897) (8,386) Net deferred tax liability $ 50,503 $ 56,182 Income tax expense reflected in our Consolidated Statements of Earnings for each of the three years ending December 31, 2018 is as follows (in millions). 2018 2017 2016 Federal $ (1,613) $ (23,427) $ 7,796 State 175 894 556 Foreign 1,117 1,018 888 $ (321) $ (21,515) $ 9,240 Current $ 5,176 $ 3,299 $ 6,565 Deferred (5,497) (24,814) 2,675 $ (321) $ (21,515) $ 9,240 Income tax expense is reconciled to hypothetical amounts computed at the U.S. federal statutory rate for each of the three years ending December 31, 2018 in the table below (in millions). 2018 2017 2016 Earnings before income taxes $ 4,001 $ 23,838 $ 33,667 Hypothetical income tax expense computed at the U.S. federal statutory rate $ 840 $ 8,343 $ 11,783 Dividends received deduction and tax exempt interest (393) (905 ) (789 ) State income taxes, less U.S. federal income tax benefit 138 465 361 Foreign tax rate differences 271 (339 ) (421 ) U.S. income tax credits (711) (636 ) (518 ) Non-taxable — — (1,143 ) Net benefit from the enactment of the TCJA (302) (28,200 ) — Other differences, net (164) (243 ) (33 ) $ (321) $ (21,515 ) $ 9,240 We file income tax returns in the United States and in state, local and foreign jurisdictions. We are under examination by the taxing authorities in many of these jurisdictions. We have settled income tax liabilities with the U.S. federal taxing authority (“IRS”) for tax years through 2011. The IRS continues to audit Berkshire’s consolidated U.S. federal income tax returns for the 2012 and 2013 tax years. We are also under audit or subject to audit with respect to income taxes in many state and foreign jurisdictions. It is reasonably possible that certain of these income tax examinations will be settled in 2019. We currently do not believe that the outcome of unresolved issues or claims will be material to our Consolidated Financial Statements. At December 31, 2018 and 2017, net unrecognized tax benefits were $549 million and $554 million, respectively. Included in the balance at December 31, 2018, were $452 million of tax positions that, if recognized, would impact the effective tax rate. The remaining balance in net unrecognized tax benefits principally relates to tax positions where the ultimate recognition is highly certain but there is uncertainty about the timing of such recognition. Because of the impact of deferred income tax accounting, the differences in recognition periods would not affect the annual effective tax rate but would accelerate the payment of cash to the taxing authority to an earlier period. As of December 31, 2018, we do not expect any material changes to the estimated amount of unrecognized tax benefits in the next twelve months.

Dividend restrictions - Insuran

Dividend restrictions - Insurance subsidiaries	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Dividend restrictions - Insurance subsidiaries	(19) Dividend restrictions – Insurance subsidiaries Payments of dividends by our insurance subsidiaries are restricted by insurance statutes and regulations. Without prior regulatory approval, our principal insurance subsidiaries may declare up to approximately $16 billion as ordinary dividends during 2019. Combined shareholders’ equity of U.S. based insurance subsidiaries determined pursuant to statutory accounting rules (Surplus as Regards Policyholders) was approximately $162 billion at December 31, 2018 and $170 billion at December 31, 2017. Statutory surplus differs from the corresponding amount based on GAAP due to differences in accounting for certain assets and liabilities. For instance, deferred charges reinsurance assumed, deferred policy acquisition costs, unrealized gains on certain investments and related deferred income taxes are recognized for GAAP but not for statutory reporting purposes. In addition, the carrying values of certain assets, such as goodwill and the carrying values of non-insurance

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	(20) Fair value measurements Our financial assets and liabilities are summarized below as of December 31, 2018 and December 31, 2017, with fair values shown according to the fair value hierarchy (in millions). The carrying values of cash and cash equivalents, U.S. Treasury Bills, receivables and accounts payable, accruals and other liabilities are considered to be reasonable estimates of their fair values. Carrying Fair Value Quoted Significant Other Significant December 31, 2018 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 4,223 $ 4,223 $ 2,933 $ 1,290 $ — States, municipalities and political subdivisions 189 189 — 189 — Foreign governments 7,502 7,502 5,417 2,085 — Corporate bonds 7,440 7,440 — 7,434 6 Mortgage-backed securities 544 544 — 544 — Investments in equity securities 172,757 172,757 172,253 203 301 Investment in Kraft Heinz common stock 13,813 14,007 14,007 — — Loans and finance receivables 16,280 16,377 — 1,531 14,846 Derivative contract assets (1) 172 172 2 52 118 Derivative contract liabilities: Railroad, utilities and energy (1) 111 111 1 101 9 Equity index put options 2,452 2,452 — — 2,452 Notes payable and other borrowings: Insurance and other 34,975 35,361 — 35,335 26 Railroad, utilities and energy 62,515 66,422 — 66,422 — December 31, 2017 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 3,953 $ 3,953 $ 2,360 $ 1,593 $ — States, municipalities and political subdivisions 854 854 — 854 — Foreign governments 8,822 8,822 6,946 1,876 — Corporate bonds 6,862 6,862 — 6,856 6 Mortgage-backed securities 862 862 — 862 — Investments in equity securities 170,540 170,540 170,494 46 — Investment in Kraft Heinz common stock 17,635 25,306 25,306 — — Loans and finance receivables 13,748 14,136 — 17 14,119 Derivative contract assets (1) 142 142 1 28 113 Derivative contract liabilities: Railroad, utilities and energy (1) 82 82 3 69 10 Equity index put options 2,172 2,172 — — 2,172 Notes payable and other borrowings: Insurance and other 40,409 41,762 — 41,757 5 Railroad, utilities and energy 62,178 70,538 — 70,538 — (1) Assets are included in other assets and liabilities are included in accounts payable, accruals and other liabilities. The fair values of substantially all of our financial instruments were measured using market or income approaches. The hierarchy for measuring fair value consists of Levels 1 through 3, which are described below. Level 1 Level 2 Level 3 Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) for each of the three years ending December 31, 2018 follow (in millions). Investments Net Balance December 31, 2015 $ 21,503 $ (3,785 ) Gains (losses) included in: Earnings 3,593 880 Other comprehensive income 872 (2 ) Regulatory assets and liabilities — (11 ) Acquisitions 10 — Dispositions and settlements (8,656 ) (101 ) Transfers into/out of Level 3 (1 ) 195 Balance December 31, 2016 17,321 (2,824 ) Gains (losses) included in: Earnings — 888 Other comprehensive income 1,157 (3 ) Regulatory assets and liabilities — (1 ) Dispositions and settlements (59 ) (129 ) Transfers into/out of Level 3 (18,413 ) — Balance December 31, 2017 6 (2,069 ) Gains (losses) included in: Earnings — (118 ) Other comprehensive income — 2 Regulatory assets and liabilities — 3 Acquisitions 302 3 Dispositions and settlements (1 ) (164 ) Balance December 31, 2018 $ 307 $ (2,343 ) Gains and losses included in earnings are reported as components of investment gains/losses, derivative gains/losses and other revenues, as appropriate. In 2017 and 2016, gains and losses included in other comprehensive income were primarily the net change in unrealized appreciation of investments and the reclassification of investment appreciation in net earnings in our Consolidated Statements of Comprehensive Income. As disclosed in Note 4, we exercised our BAC Warrants to acquire BAC common stock on August 24, 2017. As payment of the cost to acquire the BAC common stock, we surrendered substantially all of our BAC Preferred. Additionally, Restaurant Brands International Inc. (“RBI”) in December 2017, redeemed a $3 billion private placement security that we acquired in 2014. Accordingly, during 2017, we concluded the Level 3 inputs used in the previous fair value determinations of the BAC Warrants, BAC Preferred Stock and RBI investment were not significant and we transferred these measurements from Level 3 to Level 2. Quantitative information as of December 31, 2018, with respect to assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) follows (in millions). Fair Principal Valuation Unobservable Inputs Weighted Derivative contract liabilities – Equity index put options $ 2,452 Option pricing model Volatility 18% Our equity index put option contracts are illiquid and contain contract terms that are not standard in derivatives markets. For example, we are not required to post collateral under most of our contracts and certain of the contracts have relatively long durations. For these and other reasons, we classified these contracts as Level 3 measurements. The methods we use to value these contracts are those that we believe market participants would use in determining exchange prices with respect to our contracts. We value equity index put option contracts based on the Black-Scholes option valuation model. Inputs to this model include index price, contract duration and dividend and interest rate inputs (including a Berkshire non-performance

Common stock

Common stock	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Common stock	(21) Common stock Changes in Berkshire’s issued, treasury and outstanding common stock during the three years ending December 31, 2018 are shown in the table below. In addition to our common stock, 1,000,000 shares of preferred stock are authorized, but none are issued. Class A, $5 Par Value Class B, $0.0033 Par Value Issued Treasury Outstanding Issued Treasury Outstanding Balance December 31, 2015 820,102 (11,680 ) 808,422 1,253,866,598 (1,409,762 ) 1,252,456,836 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (32,044 ) — (32,044 ) 49,457,329 — 49,457,329 Balance December 31, 2016 788,058 (11,680) 776,378 1,303,323,927 (1,409,762 ) 1,301,914,165 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (25,303 ) — (25,303 ) 38,742,822 — 38,742,822 Balance December 31, 2017 762,755 (11,680 ) 751,075 1,342,066,749 (1,409,762 ) 1,340,656,987 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (20,542 ) — (20,542 ) 31,492,234 — 31,492,234 Treasury stock acquired — (1,217 ) (1,217 ) — (4,729,147 ) (4,729,147 ) Balance at December 31, 2018 742,213 (12,897 ) 729,316 1,373,558,983 (6,138,909 ) 1,367,420,074 Each Class A common share is entitled to one vote per share. Class B common stock possesses dividend and distribution rights equal to one-fifteen-hundredth one-ten-thousandth Since we have two classes of common stock, we provide earnings per share data on the Consolidated Statements of Earnings for average equivalent Class A shares outstanding and average equivalent Class B shares outstanding. Class B shares are economically equivalent to one-fifteen-hundredth one-fifteen-hundredth For several years, Berkshire had a common stock repurchase program, which permitted Berkshire to repurchase its Class A and Class B shares at prices no higher than a 20% premium over the book value of the shares. On July 17, 2018, Berkshire’s Board of Directors authorized an amendment to the program, permitting Berkshire to repurchase shares any time that Warren Buffett, Berkshire’s Chairman of the Board and Chief Executive Officer, and Charlie Munger, Vice Chairman of the Board, believe that the repurchase price is below Berkshire’s intrinsic value, conservatively determined. The program continues to allow share repurchases in the open market or through privately negotiated transactions and does not specify a maximum number of shares to be repurchased. However, repurchases will not be made if they would reduce the total value of Berkshire’s consolidated cash, cash equivalents and U.S. Treasury Bills holdings below $20 billion. The repurchase program does not obligate Berkshire to repurchase any specific dollar amount or number of Class A or Class B shares and there is no expiration date to the program.

Accumulated other comprehensive

Accumulated other comprehensive income	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated other comprehensive income	(22) Accumulated other comprehensive income A summary of the net changes in after-tax Unrealized Foreign Prior service Other Accumulated Balance December 31, 2015 $ 38,598 $ (3,856) $ (762 ) $ 2 $ 33,982 Other comprehensive income, net before reclassifications 9,011 (1,412) 94 (48 ) 7,645 Reclassifications into net earnings: Earnings before income taxes (6,820) — 104 51 (6,665) Applicable income taxes 2,387 — (29 ) (22 ) 2,336 Balance December 31, 2016 43,176 (5,268) (593 ) (17 ) 37,298 Other comprehensive income, net before reclassifications 19,826 2,151 65 16 22,058 Reclassifications into net earnings: Reclassifications before income taxes (1,399) 3 155 19 (1,222) Applicable income taxes 490 — (47 ) (6 ) 437 Balance December 31, 2017 62,093 (3,114) (420 ) 12 58,571 Reclassifications to retained earnings upon adoption of new accounting standards (61,340) (65) 36 (6 ) (61,375) Other comprehensive income, net before reclassifications (183) (1,424) (513 ) 25 (2,095) Reclassifications into net earnings: Reclassifications before income taxes (253) — 116 5 (132) Applicable income taxes 53 — (35 ) (2 ) 16 Balance December 31, 2018 $ 370 $ (4,603) $ (816 ) $ 34 $ (5,015)

Revenues from contracts with cu

Revenues from contracts with customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues from contracts with customers	(23) Revenues from contracts with customers As discussed in Note 1(w), on January 1, 2018, we adopted ASC 606 “Revenues from Contracts with Customers.” Except as described in Note 1, our revenue recognition practices for contracts with customers under ASC 606 do not differ significantly from prior practices. Under ASC 606, revenues are recognized when a good or service is transferred to a customer. A good or service is transferred when (or as) the customer obtains control of that good or service. Revenues are based on the consideration we expect to receive in connection with our promises to deliver goods and services to our customers. The following table summarizes customer contract revenues disaggregated by reportable segment and the source of the revenue for the year ended December 31, 2018 (in millions). Other revenues included in our consolidated revenues were primarily insurance premiums earned, interest, dividend and other investment income and leasing revenues which are not within the scope of ASC 606. Manufacturing McLane Service and BNSF Berkshire Insurance, Total Manufactured products: Industrial and commercial products $ 25,707 $ — $ 204 $ — $ — $ — $ 25,911 Building products 14,323 — — — — — 14,323 Consumer products 14,790 — — — — — 14,790 Grocery and convenience store distribution — 33,518 — — — — 33,518 Food and beverage distribution — 16,309 — — — — 16,309 Auto sales — — 8,181 — — — 8,181 Other retail and wholesale distribution 2,091 — 12,067 — — — 14,158 Service 1,519 84 4,100 23,652 3,949 — 33,304 Electricity and natural gas — — — — 14,951 — 14,951 Total 58,430 49,911 24,552 23,652 18,900 — 175,445 Other revenue 3,340 76 4,297 51 1,070 63,558 72,392 $ 61,770 $ 49,987 $ 28,849 $ 23,703 $ 19,970 $ 63,558 $ 247,837 A summary of the transaction price allocated to the significant unsatisfied remaining performance obligations relating to contracts with expected durations in excess of one year as of December 31, 2018 follows (in millions). Performance obligations expected to be satisfied: Less than Greater than Total Electricity and natural gas $ 842 $ 5,678 $ 6,520 Other sales and service contracts 1,190 1,904 3,094

Pension plans

Pension plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Pension plans	(24) Pension plans Several of our subsidiaries sponsor defined benefit pension plans covering certain employees. Benefits under the plans are generally based on years of service and compensation, although benefits under certain plans are based on years of service and fixed benefit rates. Our subsidiaries may make contributions to the plans to meet regulatory requirements and may also make discretionary contributions. The components of our net periodic pension expense for each of the three years ending December 31, 2018 were as follows (in millions). 2018 2017 2016 Service cost $ 271 $ 273 $ 282 Interest cost 593 635 691 Expected return on plan assets (988 ) (939 ) (908 ) Amortization of actuarial losses and other 188 157 148 Net periodic pension expense $ 64 $ 126 $ 213 The accumulated benefit obligation is the actuarial present value of benefits earned based on service and compensation prior to the valuation date. The projected benefit obligation (“PBO”) is the actuarial present value of benefits earned based upon service and compensation prior to the valuation date and, if applicable, includes assumptions regarding future compensation levels. Benefit obligations under qualified U.S. defined benefit pension plans are funded through assets held in trusts. Pension obligations under certain non-U.S. non-qualified Reconciliations of the changes in plan assets and PBOs related to BHE’s pension plans and all other pension plans for each of the two years ending December 31, 2018 are in the following tables (in millions). The costs of pension plans covering employees of certain regulated subsidiaries of BHE are generally recoverable through the regulated rate making process. 2018 2017 BHE All other Consolidated BHE All other Consolidated Benefit obligations Accumulated benefit obligation end of year $ 4,346 $ 11,540 $ 15,886 $ 4,920 $ 12,604 $ 17,524 PBO beginning of year $ 5,207 $ 13,617 $ 18,824 $ 5,077 $ 12,673 $ 17,750 Service cost 40 231 271 47 226 273 Interest cost 161 432 593 174 461 635 Benefits paid (208 ) (633 ) (841) (271 ) (626 ) (897 ) Settlements (301 ) (133 ) (434) (146 ) (95 ) (241 ) Actuarial (gains) or losses and other (348 ) (1,143 ) (1,491) 326 978 1,304 PBO end of year $ 4,551 $ 12,371 $ 16,922 $ 5,207 $ 13,617 $ 18,824 Plan assets Plan assets beginning of year $ 5,129 $ 11,885 $ 17,014 $ 4,694 $ 10,703 $ 15,397 Employer contributions 98 495 593 122 159 281 Benefits paid (208 ) (633 ) (841) (271 ) (626 ) (897 ) Actual return on plan assets (191 ) (949 ) (1,140) 535 1,601 2,136 Settlements (324 ) (132 ) (456) (159 ) (76 ) (235 ) Other (119 ) (92 ) (211) 208 124 332 Plan assets end of year $ 4,385 $ 10,574 $ 14,959 $ 5,129 $ 11,885 $ 17,014 Funded status – net liability $ 166 $ 1,797 $ 1,963 $ 78 $ 1,732 $ 1,810 The funded status of our defined benefit pension plans at December 31, 2018 reflected in assets was $510 million and in liabilities was $2,473 million. At December 31, 2017, the funded status included in assets was $1,176 million and in liabilities was $2,986 million. Weighted average assumptions used in determining PBO and net periodic pension expense were as follows. 2018 2017 2016 Discount rate applicable to pension benefit obligations 3.9% 3.3% 3.8% Expected long-term rate of return on plan assets 6.4 6.4 6.1 Rate of compensation increase 2.6 2.8 3.0 Discount rate applicable to net periodic pension expense 3.4 3.9 4.2 Benefits payments expected over the next ten years are as follows (in millions): 2019 – $1,017; 2020 – $986; 2021 – $988; 2022 – $991; 2023 – $1,001; and 2024 to 2028 – $5,027. Sponsoring subsidiaries expect to contribute $193 million to defined benefit pension plans in 2019. Fair value measurements of plan assets as of December 31, 2018 and 2017 follow (in millions). Fair Value Investment funds Total Level 1 Level 2 Level 3 December 31, 2018 Cash and cash equivalents $ 1,328 $ 1,197 $ 131 $ — $ — Equity securities 7,671 7,499 22 150 — Government obligations 1,727 1,654 73 — — Other fixed maturity securities 836 172 631 33 — Investment funds and other 3,397 170 1,042 273 1,912 $ 14,959 $ 10,692 $ 1,899 $ 456 $ 1,912 December 31, 2017 Cash and cash equivalents $ 738 $ 594 $ 144 $ — $ — Equity securities 9,824 9,641 23 160 — Government obligations 1,536 1,497 39 — — Other fixed maturity securities 799 148 619 32 — Investment funds and other 4,117 150 1,501 274 2,192 $ 17,014 $ 12,030 $ 2,326 $ 466 $ 2,192 Refer to Note 20 for a discussion of the three levels in the hierarchy of fair values. Plan assets are generally invested with the long-term objective of producing earnings to adequately cover expected benefit obligations, while assuming a prudent level of risk. Allocations may change as a result of changing market conditions and investment opportunities. The expected rates of return on plan assets reflect subjective assessments of expected invested asset returns over a period of several years. Generally, past investment returns are not given significant consideration when establishing assumptions for expected long-term rates of return on plan assets. Actual experience will differ from the assumed rates. A reconciliation of the pre-tax 2018 2017 Balance beginning of year $ (614 ) $ (839 ) Amount included in net periodic pension expense 116 155 Actuarial gains (losses) and other (686 ) 70 Balance end of year $ (1,184 ) $ (614 ) Several of our subsidiaries also sponsor defined contribution retirement plans, such as 401(k) or profit sharing plans. Employee contributions are subject to regulatory limitations and the specific plan provisions. Several plans provide for employer matching contributions up to levels specified in the plans and provide for additional discretionary contributions as determined by management. Employer contributions expensed with respect to our defined contribution plans were $1,009 million in 2018, $1,001 million in 2017 and $912 million in 2016.

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	(25) Contingencies and Commitments 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. We lease certain manufacturing, warehouse, retail and office facilities as well as certain equipment. Rent expense under operating leases was $1,649 million in 2018, $1,579 million in 2017 and $1,573 million in 2016. Future minimum rental payments for operating leases having non-cancellable 2019 2020 2021 2022 2023 After 2023 Total $1,360 $1,317 $1,098 $872 $708 $3,658 $9,013 Our subsidiaries regularly make commitments in the ordinary course of business to purchase goods and services used in their businesses. The most significant of these relate to our railroad, utilities and energy businesses and our fractional aircraft ownership business. As of December 31, 2018, estimated future payments under such arrangements were as follows: $15.7 billion in 2019, $4.5 billion in 2020, $3.7 billion in 2021, $3.2 billion in 2022, $2.9 billion in 2023 and $17.3 billion after 2023. Pursuant to the terms of agreements with noncontrolling shareholders in our less than wholly-owned subsidiaries, we may be obligated to acquire their equity interests. If we had acquired all outstanding noncontrolling interests as of December 31, 2018, we estimate the cost would have been approximately $5.6 billion. However, the timing and the amount of any such future payments that might be required are contingent on future actions of the noncontrolling owners.

Business segment data

Business segment data	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Business segment data	(26) Business segment data Our operating businesses include a large and diverse group of insurance, finance, manufacturing, service and retailing businesses. We organize our reportable business segments in a manner that reflects how management views those business activities. Certain businesses are grouped together for segment reporting based upon similar products or product lines, marketing, selling and distribution characteristics, even though those business units are operated under separate local management. The accompanying business segment information for 2017 and 2016 reflects certain reclassifications to conform to presentations in 2018. Specifically, business units that previously were reported as the finance and financial products segment were reclassified to manufacturing (Clayton Homes and UTLX), services and retailing (CORT and XTRA leasing) and corporate and other (principally investment income). The tabular information that follows shows data of reportable segments reconciled to amounts reflected in our Consolidated Financial Statements. Intersegment transactions are not eliminated from segment results when management considers those transactions in assessing the results of the respective segments. Furthermore, our management does not consider investment and derivative gains/losses, amortization of certain purchase accounting adjustments related to Berkshire’s business acquisitions or certain other corporate income and expense items in assessing the financial performance of operating units. Collectively, these items are included in reconciliations of segment amounts to consolidated amounts. Business Identity Business Activity Insurance: GEICO Underwriting private passenger automobile insurance mainly by direct response methods Berkshire Hathaway Reinsurance Group Underwriting excess-of-loss, Berkshire Hathaway Primary Group Underwriting multiple lines of property and casualty insurance policies for primarily commercial accounts BNSF Operation of one of the largest railroad systems in North America Berkshire Hathaway Energy Regulated electric and gas utility, including power generation and distribution activities and real estate brokerage activities Manufacturing Manufacturers of numerous products including industrial, consumer and building products, including manufactured housing and related consumer financing McLane Company Wholesale distribution of groceries and non-food Service and retailing Providers of numerous services including fractional aircraft ownership programs, aviation pilot training, electronic components distribution, various retailing businesses, including automobile dealerships, and trailer and furniture leasing A disaggregation of our consolidated data for each of the three most recent years is presented in the tables which follow (in millions). Revenues Earnings before income taxes 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance: Underwriting: GEICO $ 33,363 $ 29,441 $ 25,483 $ 2,449 $ (310 ) $ 462 Berkshire Hathaway Reinsurance Group 15,944 24,013 14,141 (1,109 ) (3,648 ) 1,012 Berkshire Hathaway Primary Group 8,111 7,143 6,257 670 719 657 Insurance underwriting 57,418 60,597 45,881 2,010 (3,239 ) 2,131 Investment income 5,518 4,865 4,522 5,503 4,855 4,482 Total insurance 62,936 65,462 50,403 7,513 1,616 6,613 BNSF 23,855 21,387 19,829 6,863 6,328 5,693 Berkshire Hathaway Energy 19,987 18,854 17,764 2,472 2,499 2,878 Manufacturing 61,883 57,645 52,969 9,366 8,324 7,735 McLane Company 49,987 49,775 48,075 246 299 431 Service and retailing 28,939 27,219 26,392 2,696 2,304 2,058 247,587 240,342 215,432 29,156 21,370 25,408 Reconciliation to consolidated amount: Investment and derivative gains/losses — — — (22,455 ) 2,128 8,304 Interest expense, not allocated to segments — — — (458 ) (486 ) (474 ) Equity method investments — — — (2,167 ) 3,014 1,109 Corporate, eliminations and other 250 (409 ) (318 ) (75 ) (2,188 ) (680 ) $ 247,837 $ 239,933 $ 215,114 $ 4,001 $ 23,838 $ 33,667 Interest expense Income tax expense 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ — $ — $ — $ 1,374 $ (71 ) $ 1,585 BNSF 1,041 1,016 992 1,644 2,369 2,124 Berkshire Hathaway Energy 1,777 2,254 1,715 (452 ) 148 371 Manufacturing 690 679 631 2,188 2,678 2,442 McLane Company 15 19 — 59 94 169 Service and retailing 91 67 71 634 812 761 3,614 4,035 3,409 5,447 6,030 7,452 Reconciliation to consolidated amount: Investment and derivative gains/losses — — — (4,673 ) 742 1,807 Interest expense, not allocated to segments 458 486 474 (96 ) (170 ) (166) Equity method investments — — — (753 ) 910 396 Income tax net benefit – Tax Cuts and Jobs Act of 2017 — — — — (28,200 ) — Corporate, eliminations and other (219) (135 ) (142 ) (246 ) (827 ) (249) $ 3,853 $ 4,386 $ 3,741 $ (321 ) $ (21,515 ) $ 9,240 Capital expenditures Depreciation of tangible assets 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ 130 $ 170 $ 128 $ 79 $ 84 $ 85 BNSF 3,187 3,256 3,819 2,268 2,304 2,079 Berkshire Hathaway Energy 6,241 4,571 5,090 2,830 2,548 2,560 Manufacturing 3,116 2,490 2,581 1,890 1,839 1,757 McLane Company 276 289 258 204 193 165 Service and retailing 1,587 932 1,078 1,115 751 765 $ 14,537 $ 11,708 $ 12,954 $ 8,386 $ 7,719 $ 7,411 Goodwill year-end Identifiable assets year-end 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ 15,289 $ 15,499 $ 15,474 $ 289,746 $ 294,418 $ 234,037 BNSF 14,851 14,845 14,845 70,242 69,438 69,277 Berkshire Hathaway Energy 9,851 9,935 9,266 80,543 77,710 74,571 Manufacturing 34,019 33,967 32,915 99,912 97,753 93,835 McLane Company 734 734 734 6,243 6,090 5,896 Service and retailing 6,281 6,278 6,252 24,724 20,014 19,208 $ 81,025 $ 81,258 $ 79,486 571,410 565,423 496,824 Reconciliation to consolidated amount: Corporate and other 55,359 55,414 44,544 Goodwill 81,025 81,258 79,486 $ 707,794 $ 702,095 $ 620,854 Premiums written and earned by the property/casualty and life/health insurance businesses are summarized below (in millions). Property/Casualty Life/Health 2018 2017 2016 2018 2017 2016 Premiums Written: Direct $ 44,513 $ 39,377 $ 34,001 $ 1,111 $ 866 $ 1,060 Assumed 8,970 17,815 8,037 5,540 4,925 4,672 Ceded (869 ) (694 ) (798 ) (49 ) (47 ) (62 ) $ 52,614 $ 56,498 $ 41,240 $ 6,602 $ 5,744 $ 5,670 Premiums Earned: Direct $ 43,095 $ 37,755 $ 33,207 $ 1,111 $ 866 $ 1,060 Assumed 8,649 17,813 7,848 5,438 4,866 4,671 Ceded (825 ) (677 ) (843 ) (50 ) (26 ) (62 ) $ 50,919 $ 54,891 $ 40,212 $ 6,499 $ 5,706 $ 5,669 Insurance premiums written by geographic region (based upon the domicile of the insured or reinsured) are summarized below. Dollars are in millions. Property/Casualty Life/Health 2018 2017 2016 2018 2017 2016 United States $ 46,146 $ 50,604 $ 35,878 $ 3,598 $ 3,320 $ 3,473 Asia Pacific 3,726 3,307 3,616 1,361 879 715 Western Europe 2,157 1,516 1,406 939 909 822 All other 585 1,071 340 704 636 660 $ 52,614 $ 56,498 $ 41,240 $ 6,602 $ 5,744 $ 5,670 Consolidated sales, service and leasing revenues were $139.1 billion in 2018, $132.8 billion in 2017 and $125.6 billion in 2016. In 2018, 84% of such revenues were attributable to the United States compared to 85% in 2017 and 2016. The remainder of sales, service and leasing revenues were primarily in Europe, Canada and the Asia Pacific. Consolidated sales, service and leasing revenues included sales to Walmart Stores, Inc. of approximately $13 billion in 2018 and $14 billion in 2017 and 2016. In 2018, approximately 96% of our revenues from railroad, utilities and energy businesses were in the United States compared to 95% in 2017 and 2016. At December 31, 2018, approximately 89% of our consolidated net property, plant and equipment and equipment held for lease was located in the United States with the remainder primarily in Canada and Europe.

Quarterly data

Quarterly data	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly data	(27) Quarterly data A summary of revenues and net earnings by quarter for each of the last two years follows. This information is unaudited. Amounts are in millions, except per share amounts. 1 st 2 nd 3 rd 4 th 2018 Revenues $ 58,473 $ 62,200 $ 63,450 $ 63,714 Net earnings (loss) attributable to Berkshire shareholders * (1,138 ) 12,011 18,540 (25,392 ) Net earnings (loss) attributable to Berkshire shareholders per equivalent Class A common share (692 ) 7,301 11,280 (15,467 ) 2017 Revenues $ 64,370 $ 57,256 $ 59,507 $ 58,800 Net earnings attributable to Berkshire shareholders * 4,060 4,262 4,067 32,551 Net earnings attributable to Berkshire shareholders per equivalent Class A common share 2,469 2,592 2,473 19,790 * Includes after-tax one-time 1 st 2 nd 3 rd 4 th Investment and derivative gains/losses – 2018 $ (6,426 ) $ 5,118 $ 11,660 $ (28,089 ) Investment and derivative gains/losses – 2017 504 143 623 107 Income tax net benefit – Tax Cuts and Jobs Act of 2017 — — — 28,200

Condensed Financial Information

Condensed Financial Information	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information	(Parent Company) Condensed Financial Information (Dollars in millions) Schedule I Balance Sheets December 31, 2018 2017 Assets: Cash and cash equivalents $ 3,437 $ 4,039 Short-term investments in U.S. Treasury Bills 22,957 13,132 Investments in and advances to/from consolidated subsidiaries 328,898 335,668 Investment in The Kraft Heinz Company 13,813 17,635 Other assets 80 79 $ 369,185 $ 370,553 Liabilities and Shareholders’ Equity: Accounts payable, accrued interest and other liabilities $ 1,507 $ 196 Income taxes, principally deferred 2,104 3,294 Notes payable and other borrowings 16,871 18,767 20,482 22,257 Berkshire Hathaway shareholders’ equity 348,703 348,296 $ 369,185 $ 370,553 Statements of Earnings and Comprehensive Income Year ended December 31, 2018 2017 2016 Income items: From consolidated subsidiaries: Dividends $ 9,658 $ 5,367 $ 9,862 Undistributed earnings (losses) (3,952 ) 37,832 13,264 5,706 43,199 23,126 Investment gains (losses) (4 ) (1 ) 700 Equity in net earnings (losses) of The Kraft Heinz Company (2,730 ) 2,938 923 Other income 649 350 262 3,621 46,486 25,011 Cost and expense items: General and administrative 216 159 80 Interest expense 601 522 452 Foreign exchange (gains) losses Euro-denominated senior notes (366 ) 1,008 (244 ) Income tax expense (benefit) (851 ) (143 ) 649 (400 ) 1,546 937 Net earnings attributable to Berkshire Hathaway shareholders 4,021 44,940 24,074 Other comprehensive income attributable to Berkshire Hathaway shareholders (2,211 ) 21,273 3,316 Comprehensive income attributable to Berkshire Hathaway shareholders $ 1,810 $ 66,213 $ 27,390 See Note to Condensed Financial Information BERKSHIRE HATHAWAY INC. (Parent Company) Condensed Financial Information (Dollars in millions) Schedule I (continued) Statements of Cash Flows Year ended December 31, 2018 2017 2016 Cash flows from operating activities: Net earnings attributable to Berkshire Hathaway shareholders $ 4,021 $ 44,940 $ 24,074 Adjustments to reconcile net earnings to cash flows from operating activities: Investment gains (losses) 4 1 (700 ) Undistributed earnings of consolidated subsidiaries 3,952 (37,832 ) (13,264 ) Income taxes payable (972 ) (135 ) 629 Other 3,062 (1,234 ) (161 ) Net cash flows from operating activities 10,067 5,740 10,578 Cash flows from investing activities: Redemption of Kraft Heinz Company preferred stock — — 8,320 Investments in and advances to/from consolidated subsidiaries, net 460 (239 ) (26,398 ) Purchases of U.S. Treasury Bills (29,740 ) (19,663 ) (9,350 ) Sales and maturities of U.S. Treasury Bills 21,442 14,847 1,145 Net cash flows from investing activities (7,838 ) (5,055 ) (26,283 ) Cash flows from financing activities: Proceeds from borrowings 17 1,201 9,278 Repayments of borrowings (1,563 ) (1,145 ) (1,125 ) Acquisition of treasury stock (1,346 ) — — Other 61 77 164 Net cash flows from financing activities (2,831 ) 133 8,317 Increase (decrease) in cash and cash equivalents (602 ) 818 (7,388 ) Cash and cash equivalents at beginning of year 4,039 3,221 10,609 Cash and cash equivalents at end of year $ 3,437 $ 4,039 $ 3,221 Other cash flow information: Income taxes paid $ 2,790 $ 2,076 $ 3,583 Interest paid 388 386 307 Note to Condensed Financial Information Berkshire acquired 50% of the outstanding common stock of Heinz Holding Company in 2013. After a series of transactions in 2015, that interest represented 26.8% of the outstanding common stock of The Kraft Heinz Company (“Kraft Heinz”). Berkshire currently owns 26.7% of the outstanding shares of Kraft Heinz common stock. Reference is made to Note 5 to the Consolidated Financial Statements for additional information concerning Berkshire’s investment in Kraft Heinz. Prior to 2018, the Parent Company issued Euro-denominated senior notes and the aggregate par amount outstanding of these borrowings was €6.85 billion as of December 31, 2018 and 2017. The gains and losses from the periodic remeasurement of the Euro notes due to changes in foreign currency exchange rates are included in earnings. Parent Company debt maturities over the next five years are as follows: 2019—$752 million; 2020—$1,149 million; 2021—$2,131 million; 2022—$613 million and 2023—$3,991 million. Berkshire guarantees debt obligations of certain of its subsidiaries, which as of December 31, 2018, totaled approximately $12.4 billion. Such guarantees are an absolute, unconditional and irrevocable guarantee for the full and prompt payment when due of all present and future payment obligations. Berkshire also provides guarantees in connection with equity index put option contracts and certain retroactive reinsurance contracts of subsidiaries. The amounts of subsidiary payments under these contracts, if any, is contingent upon the outcome of future events. In December 2017, the Tax Cuts and Jobs Act of 2017 (“TCJA”) was enacted, which reduced the Parent Company’s income tax expense in 2017 by $550 million, primarily due to the reduction in deferred tax liabilities attributable to the lower U.S. statutory rate, partly offset by a one-time

Significant accounting polici_2

Significant accounting policies and practices (Policies)	12 Months Ended
	Dec. 31, 2018
Nature of operations and basis of consolidation	(a) Nature of operations and basis of consolidation Berkshire Hathaway Inc. (“Berkshire”) is a holding company owning subsidiaries engaged in a number of diverse business activities, including insurance and reinsurance, freight rail transportation, utilities and energy, manufacturing, service, retailing and finance. In these notes the terms “us,” “we,” or “our” refer to Berkshire and its consolidated subsidiaries. Further information regarding our reportable business segments is contained in Note 26. Information concerning significant business acquisitions completed over the past three years appears in Note 2. The Consolidated Financial Statements for periods before 2018 reflect reclassifications to conform to 2018 presentations. Most significantly, line items previously reported under the sub-caption The accompanying Consolidated Financial Statements include the accounts of Berkshire consolidated with the accounts of all subsidiaries and affiliates in which we hold a controlling financial interest as of the financial statement date. Normally a controlling financial interest reflects ownership of a majority of the voting interests. We consolidate variable interest entities (“VIE”) when we possess both the power to direct the activities of the VIE that most significantly affect its economic performance, and we (a) are obligated to absorb the losses that could be significant to the VIE or (b) hold the right to receive benefits from the VIE that could be significant to the VIE. Intercompany accounts and transactions have been eliminated.
Use of estimates in preparation of financial statements	(b) Use of estimates in preparation of financial statements The preparation of our Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. In particular, estimates of unpaid losses and loss adjustment expenses are subject to considerable estimation error due to the inherent uncertainty in projecting ultimate claim costs. In addition, estimates and assumptions associated with the amortization of deferred charges on retroactive reinsurance contracts, determinations of fair values of certain financial instruments and evaluations of goodwill and identifiable intangible assets for impairment require considerable judgment. Actual results may differ from the estimates used in preparing our Consolidated Financial Statements.
Cash and cash equivalents and short-term investments in U.S. Treasury Bills	(c) Cash and cash equivalents and short-term investments in U.S. Treasury Bills Cash equivalents consist of demand deposit and money market accounts and investments with maturities of three months or less when purchased. Short-term investments in U.S. Treasury Bills with remaining maturities exceeding three months at the time of purchase are stated at amortized cost, which approximates fair value.
Investments under the equity method	(f) Investments under the equity method We utilize the equity method to account for investments when we possess the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when the investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate that the ability to exercise significant influence is restricted. We apply the equity method to investments in common stock and to other investments when such other investments possess substantially identical subordinated interests to common stock. In applying the equity method, we record the investment at cost and subsequently increase or decrease the carrying amount of the investment by our proportionate share of the net earnings or losses and other comprehensive income of the investee. We record dividends or other equity distributions as reductions in the carrying value of the investment. In the event that net losses of the investee reduce the carrying amount to zero, additional net losses may be recorded if other investments in the investee are at-risk,
Receivables	(g) Receivables Receivables primarily consists of balances due from customers, insurance premiums receivable and reinsurance recoverable on unpaid losses. Receivables are stated net of estimated allowances for uncollectible balances. Allowances for uncollectible balances are provided when it is probable counterparties or customers will be unable to pay all amounts due based on the contractual terms. We write-off
Loans and finance receivables	(h) Loans and finance receivables Loans and finance receivables are predominantly manufactured housing installment loans. We carry these loans at amortized cost, net of allowances for uncollectible accounts, based on our ability and intent to hold such loans to maturity. Acquisition costs and loan origination and commitment costs paid or fees received along with acquisition premiums or discounts are amortized as yield adjustments over the lives of the loans. Substantially all of our loans and finance receivables are secured by real or personal property or by other assets of the borrower. Allowances for credit losses on loans include estimates of losses on loans currently in foreclosure and losses on loans not currently in foreclosure. We estimate losses on loans in foreclosure based on historical experience and collateral recovery rates. Estimates of losses on loans not currently in foreclosure consider historical default rates, collateral recovery rates and prevailing economic conditions. Allowances for credit losses also incorporate the historical average time elapsed from the last payment until foreclosure. Loans are considered delinquent when payments are more than 30 days past due. We place loans over 90 days past due on nonaccrual status and accrued but uncollected interest is reversed. Subsequent collections on the loans are first applied to the principal and interest owed for the most delinquent amount. We resume interest income accrual once a loan is less than 90 days delinquent. Loans in the foreclosure process are considered non-performing.
Derivatives	(i) Derivatives We carry derivative contracts in our Consolidated Balance Sheets at fair value, net of reductions permitted under master netting agreements with counterparties. We record the changes in fair value of derivative contracts that do not qualify as hedging instruments for financial reporting purposes in earnings or by our regulated utilities businesses as regulatory assets or liabilities, as applicable, when inclusion in regulated rates is probable.
Fair value measurements	(j) Fair value measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Alternative valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not acting under duress. Our nonperformance or credit risk is considered in determining the fair value of liabilities. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Inventories	(k) Inventories Inventories consist of manufactured goods, goods acquired for resale, homes constructed for sale, and materials consumed in business operations. Manufactured inventory costs include raw materials, direct and indirect labor and factory overhead. We used the last-in-first-out first-in-first-out Non-LIFO
Property, plant and equipment	(l) Property, plant and equipment We record additions to property, plant and equipment used in operations at cost, which includes asset additions, improvements and betterments. With respect to constructed assets, all materials, direct labor and contract services as well as certain indirect costs are capitalized. Indirect costs include interest over the construction period. With respect to constructed assets of our utility and energy subsidiaries that are subject to authoritative guidance for regulated operations, capitalized costs also include an equity allowance for funds used during construction, which represents the cost of equity funds used to finance the construction of the regulated facilities. See Note 1(t). Normal repairs and maintenance and other costs that do not improve the property, extend the useful life or otherwise do not meet capitalization criteria are charged to expense as incurred. Rail grinding costs related to our railroad properties are expensed as incurred. Depreciation of assets of our regulated utilities and railroad is generally determined using group depreciation methods where rates are based on periodic depreciation studies approved by the applicable regulator. Under group depreciation, a single depreciation rate is applied to the gross investment in a particular class of property, despite differences in the service life or salvage value of individual property units within the same class. When such assets are retired or sold, no gain or loss is recognized. Gains or losses on disposals of all other assets are recorded through earnings. We depreciate property, plant and equipment used by our other businesses to estimated salvage value primarily using the straight-line method over estimated useful lives. Ranges of estimated useful lives of depreciable assets used in our other businesses are as follows: buildings and improvements – 5 to 50 years, machinery and equipment – 3 to 25 years and furniture, fixtures and other – 3 to 15 years. Ranges of estimated useful lives of depreciable assets unique to our railroad business are as follows: track structure and other roadway – 9 to 100 years and locomotives, freight cars and other equipment – 6 to 41 years. Ranges of estimated useful lives of assets unique to our regulated utilities and energy businesses are as follows: utility generation, transmission and distribution systems – 5 to 80 years, interstate natural gas pipeline assets – 3 to 80 years and independent power plants and other assets – 3 to 30 years. We evaluate property, plant and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or when the assets are held for sale. Upon the occurrence of a triggering event, we assess whether the estimated undiscounted cash flows expected from the use of the asset and the residual value from the ultimate disposal of the asset exceeds the carrying value. If the carrying value exceeds the estimated recoverable amounts, we reduce the carrying value to fair value and record an impairment loss in earnings, except with respect to impairment of assets of our regulated utility and energy subsidiaries where the impacts of regulation are considered in evaluating the carrying value.
Equipment held for lease	(m) Equipment held for lease We record additions to equipment held for lease at cost. We depreciate equipment held for lease to estimated salvage value primarily using the straight-line method over estimated useful lives ranging from 6 to 35 years. We also evaluate equipment held for lease for impairment consistent with policies for property, plant and equipment.
Goodwill and other intangible assets	(n) Goodwill and other intangible assets Goodwill represents the excess of the acquisition price of a business over the fair value of identified net assets of that business. We evaluate goodwill for impairment at least annually. When evaluating goodwill for impairment, we estimate the fair value of the reporting unit. There are several methods that may be used to estimate a reporting unit’s fair value, including market quotations, asset and liability fair values and other valuation techniques, including, but not limited to, discounted projected future net earnings or net cash flows and multiples of earnings. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. We amortize intangible assets with finite lives in a pattern that reflects the expected consumption of related economic benefits or on a straight-line basis over the estimated economic lives. Intangible assets with finite lives are reviewed for impairment when events or changes in circumstances indicate that the carrying amount may not be recoverable. Intangible assets with indefinite lives are tested for impairment at least annually and when events or changes in circumstances indicate that, more-likely-than-not,
Revenue recognition	(o) Revenue recognition We earn insurance premiums on prospective property/casualty insurance and reinsurance contracts over the loss exposure or coverage period in proportion to the level of protection provided. In most cases, such premiums are earned ratably over the term of the contract with unearned premiums computed on a monthly or daily pro-rata On January 1, 2018, we adopted Accounting Standards Codification (“ASC”) 606 “Revenues from Contracts with Customers.” Except as described in Note 1(w), our revenue recognition practices for contracts with customers under ASC 606 do not differ significantly from prior practices. Under ASC 606, revenues are recognized when a good or service is transferred to a customer. A good or service is transferred when (or as) the customer obtains control of that good or service. Revenues are based on the consideration we expect to receive in connection with our promises to deliver goods and services to our customers. We manufacture and/or distribute a wide variety of industrial, building and consumer products. Our sales contracts provide customers with these products through wholesale and retail channels in exchange for consideration specified under the contracts. Contracts generally represent customer orders for individual products at stated prices. Sales contracts may contain either single or multiple performance obligations. In instances where contracts contain multiple performance obligations, we allocate the revenue to each obligation based on the relative stand-alone selling prices of each product or service. Sales revenue reflects reductions for returns, allowances, volume discounts and other incentives, some of which may be contingent on future events. In certain customer contracts, sales revenue includes certain state and local excise taxes billed to customers on specified products when those taxes are levied directly upon us by the taxing authorities. Sales revenue excludes sales taxes and value-added taxes collected on behalf of taxing authorities. Sales revenue includes consideration for shipping and other fulfillment activities performed prior to the customer obtaining control of the goods. We also elect to treat consideration for such services performed after control has passed to the customer as sales revenue. Our product sales revenues are generally recognized at a point in time when control of the product transfers to the customer, which coincides with customer pickup or product delivery or acceptance, depending on terms of the arrangement. We recognize sales revenues and related costs with respect to certain contracts over time, primarily from certain castings, forgings and aerostructures contracts. Control of the product units under these contracts transfers continuously to the customer as the product is manufactured. These products generally have no alternative use and the contract requires the customer to provide reasonable compensation if terminated for reasons other than breach of contract. Our energy revenue derives primarily from tariff based sales arrangements approved by various regulatory commissions. These tariff based revenues are mainly comprised of energy, transmission, distribution and natural gas and have performance obligations to deliver energy products and services to customers which are satisfied over time as energy is delivered or services are provided. Our nonregulated energy revenue primarily relates to our renewable energy business. Energy revenues are equivalent to the amounts we have the right to invoice and correspond directly with the value to the customer of the performance to date and include billed and unbilled amounts. Payments from customers are generally due from the customer within 30 days of billing. Rates charged for energy products and services are established by regulators or contractual arrangements that establish the transaction price, as well as the allocation of price amongst the separate performance obligations. When preliminary regulated rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. The primary performance obligation under our freight rail transportation service contracts is to move freight from a point of origin to a point of destination. The performance obligations are represented by bills of lading which create a series of distinct services that have a similar pattern of transfer to the customer. The revenues for each performance obligation are based on various factors including the product being shipped, the origin and destination pair, and contract incentives which are outlined in various private rate agreements, common carrier public tariffs, interline foreign road agreements and pricing quotes. The transaction price is generally a per car amount to transport railcars from a specified origin to a specified destination. Freight revenues are recognized over time as the service is performed because the customer simultaneously receives and consumes the benefits of the service. Revenues recognized represent the proportion of the service completed as of the balance sheet date. Invoices for freight transportation services are generally issued to customers and paid within 30 days or less. Customer incentives, which are primarily provided for shipping a specified cumulative volume or shipping to/from specific locations, are recorded as a reduction to revenue on a pro-rata Other service revenues derive from contracts with customers in which performance obligations are satisfied over time, where customers receive and consume benefits as we perform the services, or at a point in time when the services are provided. Other service revenues primarily derive from real estate brokerage, automotive repair, aircraft management, aviation training, franchising and news distribution services. Leasing revenue is generally recognized ratably over the term of the lease or based on usage, if applicable under the terms of the contract. A substantial portion of our leases are classified as operating leases. Prior to January 1, 2018, we recognized revenues from the sales of fractional ownership interests in aircraft over the term of the related management services agreements, as the transfers of the ownership interests were inseparable from the management services agreements. These agreements also include provisions that require us to repurchase the fractional interest at fair market value at contract termination or upon the customer’s request following the end of a minimum commitment period. ASC 606 provides that such contracts are subject to accounting guidance for lease contracts and not ASC 606. The re-characterization
Losses and loss adjustment expenses	(p) Losses and loss adjustment expenses We record liabilities for unpaid losses and loss adjustment expenses assumed under short duration property/casualty insurance and reinsurance contracts for loss events that have occurred on or before the balance sheet date. Such liabilities represent the estimated ultimate payment amounts without discounting for time value. We base liability estimates on (1) reports of losses from policyholders, (2) individual case estimates and (3) estimates of incurred but not reported losses. Losses and loss adjustment expenses in the Consolidated Statements of Earnings include paid claims, claim settlement costs and changes in estimated claim liabilities. Losses and loss adjustment expenses charged to earnings are net of amounts recovered and estimates of recoverable amounts under ceded reinsurance contracts. Reinsurance contracts do not relieve the ceding company of its obligations to indemnify policyholders with respect to the underlying insurance and reinsurance contracts.
Retroactive reinsurance contracts	(q) Retroactive reinsurance contracts We record liabilities for unpaid losses and loss adjustment expenses assumed under retroactive reinsurance of short duration contracts consistent with other short duration property/casualty insurance and reinsurance contracts discussed in Note 1(p). With respect to retroactive reinsurance contracts, we also record deferred charge assets at the inception of the contracts, representing the excess, if any, of the estimated ultimate claim liabilities over the premiums earned. We subsequently amortize the deferred charge assets over the expected claim settlement periods using the interest method. Changes to the estimated timing or amount of future loss payments also produce changes in deferred charge balances. We apply changes in such estimates retrospectively and the resulting changes in deferred charge balances, together with periodic amortization, are included in insurance losses and loss adjustment expenses in the Consolidated Statements of Earnings.
Insurance policy acquisition costs	(r) Insurance policy acquisition costs We capitalize the incremental costs that directly relate to the successful sale of insurance contracts, subject to ultimate recoverability, and we subsequently amortize such costs to underwriting expenses as the related premiums are earned. Direct incremental acquisition costs include commissions, premium taxes and certain other costs associated with successful efforts. We expense all other underwriting costs as incurred. The recoverability of capitalized insurance policy acquisition costs generally reflects anticipation of investment income. The unamortized balances are included in other assets and were $2,658 million and $2,529 million at December 31, 2018 and 2017, respectively.
Life and annuity insurance benefits	(s) Life and annuity insurance benefits We compute our liabilities for insurance benefits under life contracts based upon estimated future investment yields, expected mortality, morbidity, and lapse or withdrawal rates as well as estimates of premiums we expect to receive and expenses we expect to incur in the future. These assumptions, as applicable, also include a margin for adverse deviation and may vary with the characteristics of the contract’s date of issuance, policy duration and country of risk. The interest rate assumptions used may vary by contract or jurisdiction. We discount periodic payment annuity liabilities based on the implicit rate as of the inception of the contracts such that the present value of the liabilities equals the premiums. Discount rates range from less than 1% to 7%.
Regulated utilities and energy businesses	(t) Regulated utilities and energy businesses Certain energy subsidiaries prepare their financial statements in accordance with authoritative guidance for regulated operations, reflecting the economic effects of regulation from the ability to recover certain costs from customers and the requirement to return revenues to customers in the future through the regulated rate-setting process. Accordingly, certain costs are deferred as regulatory assets and certain income is accrued as regulatory liabilities. Regulatory assets and liabilities will be amortized into operating expenses and revenues over various future periods. Regulatory assets and liabilities are continually assessed for probable future inclusion in regulatory rates by considering factors such as applicable regulatory or legislative changes and recent rate orders received by other regulated entities. If future inclusion in regulatory rates ceases to be probable, the amount no longer probable of inclusion in regulatory rates is charged or credited to earnings (or other comprehensive income, if applicable) or returned to customers.
Foreign currency	(u) Foreign currency The accounts of our non-U.S.
Income taxes	(v) Income taxes Berkshire files a consolidated federal income tax return in the United States, which includes eligible subsidiaries. In addition, we file income tax returns in state, local and foreign jurisdictions as applicable. Provisions for current income tax liabilities are calculated and accrued on income and expense amounts expected to be included in the income tax returns for the current year. Income taxes reported in earnings also include deferred income tax provisions. Deferred income tax assets and liabilities are computed on differences between the financial statement bases and tax bases of assets and liabilities at the enacted tax rates. Changes in deferred income tax assets and liabilities associated with components of other comprehensive income are charged or credited directly to other comprehensive income. Otherwise, changes in deferred income tax assets and liabilities are included as a component of income tax expense. The effect on deferred income tax assets and liabilities attributable to changes in enacted tax rates are charged or credited to income tax expense in the period of enactment. Valuation allowances are established for certain deferred tax assets when realization is not likely. Assets and liabilities are established for uncertain tax positions taken or positions expected to be taken in income tax returns when such positions, in our judgment, do not meet a more-likely-than-not
New accounting pronouncements adopted in 2018	(w) New accounting pronouncements adopted in 2018 On January 1, 2018, we adopted Accounting Standards Update (“ASU”) 2016-01 2018-02 2016-01, 2018-02 ASU 2016-01 ASU 2018-02 ASC 606 Total Increase (decrease): Assets $ — $ — $ 3,382 $ 3,382 Liabilities — — 3,453 3,453 Accumulated other comprehensive income (61,459) 84 — (61,375) Retained earnings 61,459 (84) (70) 61,305 Shareholders’ equity — — (70) (70) With respect to ASU 2016-01, after-tax In adopting ASU 2018-02, In adopting ASC 606, we recorded increases to certain assets and other liabilities, with the cumulative net effect recorded to retained earnings. Prior to January 1, 2018, we recognized revenues from the sales of fractional ownership interests in aircraft over the term of the related management services agreements, as the transfers of the ownership interests were inseparable from the management services agreements. These agreements also include provisions that require us to repurchase the fractional interest at fair market value at contract termination or upon the customer’s request following the end of a minimum commitment period. ASC 606 provides that such contracts are subject to accounting guidance for lease contracts. The principal effects of this re-characterization
New accounting pronouncements to be adopted subsequent to December 31, 2018	(x) New accounting pronouncements to be adopted subsequent to December 31, 2018 In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02 We are party to contracts where we are the lessee and other contracts where we are the lessor. For contracts where we are the lessee, our consolidated assets and liabilities increased by approximately $6 billion as of January 1, 2019, primarily due to the recognition of right-of-use In June 2016, the FASB issued ASU 2016-13 available-for-sale 2016-13 In January 2017, the FASB issued ASU 2017-04 2017-04 2017-04, 2017-04 In August 2018, the FASB issued ASU 2018-12 2018-12 2018-12
Fixed Maturities [Member]
Investments in fixed maturity and equity securities	(d) Investments in fixed maturity securities We classify investments in fixed maturity securities at the acquisition date and re-evaluate held-to-maturity available-for-sale available-for-sale. Investment gains and losses arise when fixed maturity securities are sold (as determined on a specific identification basis) or are other-than-temporarily impaired with respect to securities classified as available-for-sale.
Equity Securities [Member]
Investments in fixed maturity and equity securities	(e) Investments in equity securities We carry substantially all of our investments in equity securities at fair value and record the subsequent changes in fair values in the Consolidated Statement of Earnings as a component of investment gains/losses. Prior to January 1, 2018, substantially all of our equity security investments were classified as available-for-sale

Significant accounting polici_3

Significant accounting policies and practices (Tables)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of effects of initial adoption of ASU 2016-01, ASU 2018-02 and ASC 606	A summary of the effects of the initial adoption of ASU 2016-01, 2018-02 ASU 2016-01 ASU 2018-02 ASC 606 Total Increase (decrease): Assets $ — $ — $ 3,382 $ 3,382 Liabilities — — 3,453 3,453 Accumulated other comprehensive income (61,459) 84 — (61,375) Retained earnings 61,459 (84) (70) 61,305 Shareholders’ equity — — (70) (70)

Significant business acquisit_2

Significant business acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of estimated fair values of assets acquired and liabilities assumed	The fair values of identified assets acquired and liabilities assumed and residual goodwill at their respective acquisition dates are summarized as follows (in millions). PCC Duracell Cash and cash equivalents $ 250 $ 1,807 Inventories 3,430 319 Property, plant and equipment 2,765 359 Goodwill 16,011 866 Other intangible assets 23,527 1,550 Other assets 1,916 242 Assets acquired $ 47,899 $ 5,143 Accounts payable, accruals and other liabilities $ 2,442 $ 410 Notes payable and other borrowings 5,251 — Income taxes, principally deferred 7,548 494 Liabilities assumed $ 15,241 $ 904 Net assets $ 32,658 $ 4,239

Investments in fixed maturity_2

Investments in fixed maturity securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in securities with fixed maturities	Investments in fixed maturity securities as of December 31, 2018 and 2017 are summarized by type below (in millions). Amortized Unrealized Unrealized Fair December 31, 2018 U.S. Treasury, U.S. government corporations and agencies $ 4,223 $ 22 $ (22) $ 4,223 States, municipalities and political subdivisions 182 7 — 189 Foreign governments 7,480 50 (28) 7,502 Corporate bonds 7,055 408 (23) 7,440 Mortgage-backed securities 487 59 (2) 544 $ 19,427 $ 546 $ (75) $ 19,898 December 31, 2017 U.S. Treasury, U.S. government corporations and agencies $ 3,975 $ 4 $ (26) $ 3,953 States, municipalities and political subdivisions 847 19 (12) 854 Foreign governments 8,572 274 (24) 8,822 Corporate bonds 6,279 588 (5) 6,862 Mortgage-backed securities 772 92 (2) 862 $ 20,445 $ 977 $ (69) $ 21,353
Schedule of amortized cost and estimated fair value of securities with fixed maturities	The amortized cost and estimated fair value of fixed maturity securities at December 31, 2018 are summarized below by contractual maturity dates. Amounts are in millions. Actual maturities may differ from contractual maturities due to early call or prepayment rights held by issuers. Due in one Due after one Due after five Due after Mortgage-backed Total Amortized cost $ 6,973 $ 10,937 $ 438 $ 592 $ 487 $ 19,427 Fair value 6,982 10,994 494 884 544 19,898

Investments in equity securit_2

Investments in equity securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in equity securities	Investments in equity securities as of December 31, 2018 and 2017 are summarized based on the primary industry of the investee in the table below (in millions). Cost Basis Net Fair December 31, 2018 Banks, insurance and finance $ 44,332 $ 38,260 $ 82,592 Consumer products 38,783 22,838 61,621 Commercial, industrial and other 19,752 8,792 28,544 $ 102,867 $ 69,890 $ 172,757 * Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company – $14.5 billion; Apple Inc. – $40.3 billion; Bank of America Corporation – $22.6 billion; The Coca-Cola Company – $18.9 billion and Wells Fargo & Company – $20.7 billion). Cost Basis Net Unrealized Gains Fair December 31, 2017 Banks, insurance and finance $ 25,783 $ 55,026 $ 80,809 Consumer products 25,177 25,698 50,875 Commercial, industrial and other 23,716 15,140 38,856 $ 74,676 $ 95,864 $ 170,540 * Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company – $15.1 billion; Apple Inc. – $28.2 billion; Bank of America Corporation – $20.7 billion; The Coca-Cola Company – $18.4 billion and Wells Fargo & Company – $29.3 billion).

Equity method investments (Tabl

Equity method investments (Tables)	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Summarized unaudited financial information of Kraft Heinz	Summarized unaudited financial information of Kraft Heinz follows (in millions). December 29, December 30, Assets $ 103,627 $ 120,232 Liabilities 51,721 53,985 Year ending Year ending Year ending Sales $ 26,259 $ 26,085 $ 26,335 Net earnings (losses) attributable to Kraft Heinz common shareholders $ (10,229) $ 10,999 $ 3,452

Investment gains_losses (Tables

Investment gains/losses (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of investment gains and losses	Investment gains/losses for each of the three years ending December 31, 2018 are summarized below (in millions). 2018 2017 2016 Equity securities: Unrealized investment gains/losses on securities held at the end of the period $ (22,729) $ — $ — Investment gains/losses during 2018 on securities sold in 2018 291 — — Gross realized gains — 2,237 7,853 Gross realized losses — (919) (415) (22,438) 1,318 7,438 Fixed maturity securities: Gross realized gains 480 103 58 Gross realized losses (227) (22) (51) Other 30 11 108 $ (22,155) $ 1,410 $ 7,553

Loans and finance receivables (

Loans and finance receivables (Tables)	12 Months Ended
	Dec. 31, 2018
Insurance and Other [Member]
Schedule of receivables	Other receivables of insurance and other businesses are comprised of the following (in millions). December 31, 2018 2017 Insurance premiums receivable $ 12,452 $ 11,058 Reinsurance recoverable on unpaid losses 3,060 3,201 Trade receivables 12,617 12,031 Other 3,823 3,464 Allowances for uncollectible accounts (388 ) (362 ) $ 31,564 $ 29,392
Railroad, Utilities and Energy [Member]
Schedule of receivables	Receivables of our railroad and our utilities and energy businesses are comprised of the following (in millions). December 31, 2018 2017 Trade receivables $ 3,433 $ 3,346 Other 362 313 Allowances for uncollectible accounts (129 ) (128 ) $ 3,666 $ 3,531
Loans and Finance Receivables [Member]
Schedule of receivables	Loans and finance receivables are summarized as follows (in millions). December 31, 2018 2017 Loans and finance receivables before allowances and discounts $ 16,622 $ 14,126 Allowances for uncollectible loans (177 ) (180 ) Unamortized acquisition discounts (165 ) (198 ) $ 16,280 $ 13,748

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories are comprised of the following (in millions). December 31, 2018 2017 Raw materials $ 4,182 $ 3,479 Work in process and other 2,625 2,568 Finished manufactured goods 4,541 4,505 Goods acquired for resale 7,721 6,814 $ 19,069 $ 17,366

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of depreciation expense	Depreciation expense for each of the three years ending December 31, 2018 is summarized below (in millions). 2018 2017 2016 Insurance and other $ 2,186 $ 2,116 $ 2,017 Railroad, utilities and energy 5,098 4,852 4,639 $ 7,284 $ 6,968 $ 6,656
Schedule of equipment held for lease	Equipment held for lease is summarized below (in millions). Equipment held for lease includes railcars, aircraft, over-the-road December 31, 2018 2017 Railcars $ 8,862 $ 8,352 Aircraft 7,376 1,456 Other equipment held for lease 4,379 3,967 20,617 13,775 Accumulated depreciation (6,319 ) (3,608) $ 14,298 $ 10,167
Insurance and Other [Member]
Schedule of property, plant and equipment	A summary of property, plant and equipment of our insurance and other businesses follows (in millions). December 31, 2018 2017 Land $ 2,536 $ 2,523 Buildings and improvements 9,959 9,409 Machinery and equipment 22,574 21,190 Furniture, fixtures and other 4,758 4,519 39,827 37,641 Accumulated depreciation (19,199 ) (17,773 ) $ 20,628 $ 19,868
Railroad, Utilities and Energy [Member]
Schedule of property, plant and equipment	A summary of property, plant and equipment of our railroad and our utilities and energy businesses follows (in millions). The utility generation, transmission and distribution systems and interstate natural gas pipeline assets are owned by regulated public utility and natural gas pipeline subsidiaries. December 31, 2018 2017 Railroad: Land, track structure and other roadway $ 59,509 $ 57,408 Locomotives, freight cars and other equipment 13,016 12,543 Construction in progress 664 989 73,189 70,940 Accumulated depreciation (10,004 ) (8,627 ) 63,185 62,313 Utilities and energy: Utility generation, transmission and distribution systems 77,288 74,660 Interstate natural gas pipeline assets 7,524 7,176 Independent power plants and other assets 8,324 7,499 Construction in progress 3,110 2,556 96,246 91,891 Accumulated depreciation (27,651 ) (26,020 ) 68,595 65,871 $ 131,780 $ 128,184

Goodwill and other intangible_2

Goodwill and other intangible assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Reconciliation of the change in goodwill	Reconciliations of the changes in the carrying value of goodwill during 2018 and 2017 follows (in millions). December 31, 2018 2017 Balance at beginning of year $ 81,258 $ 79,486 Acquisitions of businesses 376 1,545 Other, including foreign currency translation (609 ) 227 Balance at end of year $ 81,025 $ 81,258
Schedule of intangible assets	Our other intangible assets and related accumulated amortization are summarized as follows (in millions). December 31, 2018 December 31, 2017 Gross carrying Accumulated Gross carrying Accumulated Insurance and other $ 40,493 $ 8,994 $ 40,225 $ 7,707 Railroad, utilities and energy 1,011 362 988 324 $ 41,504 $ 9,356 $ 41,213 $ 8,031 Trademarks and trade names $ 5,368 $ 750 $ 5,381 $ 692 Patents and technology 4,446 2,790 4,341 2,493 Customer relationships 28,375 4,573 28,322 3,722 Other 3,315 1,243 3,169 1,124 $ 41,504 $ 9,356 $ 41,213 $ 8,031

Derivative contracts (Tables)

Derivative contracts (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative contracts outstanding	The liabilities and related notional values of these contracts follows (in millions). Liabilities Notional December 31, 2018 $ 2,452 $ 26,759 December 31, 2017 2,172 28,753

Supplemental cash flow inform_2

Supplemental cash flow information (Tables)	12 Months Ended
	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Schedule of supplemental cash flow information	A summary of supplemental cash flow information for each of the three years ending December 31, 2018 is presented in the following table (in millions). 2018 2017 2016 Cash paid during the period for: Income taxes $ 4,354 $ 3,286 $ 4,719 Interest: Insurance and other 1,111 1,260 944 Railroad, utilities and energy 2,867 2,828 2,788 Non-cash Liabilities assumed in connection with business acquisitions 3,735 747 16,555 Equity securities exchanged in connection with business acquisitions — — 4,239 Conversions and other exchanges of investments — — 4,154 Equity securities surrendered in connection with warrant exercise — 4,965 —

Unpaid losses and loss adjust_2

Unpaid losses and loss adjustment expenses (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of liability for unpaid claims and claims adjustment expense	A reconciliation of the changes in claim liabilities, excluding liabilities under retroactive reinsurance contracts (see Note 16), for each of the three years ending December 31, 2018 is as follows (in millions). 2018 2017 2016 Balances – beginning of year: Gross liabilities $ 61,122 $ 53,379 $ 50,519 Reinsurance recoverable on unpaid losses (3,201 ) (3,338 ) (3,307 ) Net liabilities 57,921 50,041 47,212 Incurred losses and loss adjustment expenses: Current accident year events 39,876 37,702 30,636 Prior accident years’ events (1,406 ) (544 ) (1,443 ) Total incurred losses and loss adjustment expenses 38,470 37,158 29,193 Paid losses and loss adjustment expenses: Current accident year events (18,391 ) (17,425 ) (14,898 ) Prior accident years’ events (15,452 ) (12,507 ) (10,929 ) Total payments (33,843 ) (29,932 ) (25,827 ) Foreign currency translation adjustment (331 ) 654 (537 ) Business acquisition 3,181 — — Balances – end of year: Net liabilities 65,398 57,921 50,041 Reinsurance recoverable on unpaid losses 3,060 3,201 3,338 Gross liabilities $ 68,458 $ 61,122 $ 53,379
Schedule of reconciliation of unpaid losses and allocated loss adjustment expenses to balance sheet liability	A reconciliation of the disaggregated net unpaid losses and allocated loss adjustment expenses (the latter referred to as “ALAE”) of GEICO, Berkshire Hathaway Reinsurance Group (“BHRG”) and Berkshire Hathaway Primary Group (“BH Primary”) to our consolidated unpaid losses and loss adjustment expenses as of December 31, 2018, follows (in millions). GEICO BHRG BHRG BH Primary BH Primary Total Unpaid losses and ALAE, net $ 17,318 $ 9,395 $ 19,966 $ 7,288 $ 8,694 $ 62,661 Reinsurance recoverable 896 312 850 53 940 3,051 Unpaid unallocated loss adjustment expenses 2,015 Other unpaid losses and loss adjustment expenses 731 Unpaid losses and loss adjustment expenses $ 68,458
Schedule of average historical claims duration	Supplemental unaudited average historical claims duration information based on the net losses and ALAE incurred and paid accident year data in the preceding tables follows. The percentages show the average portions of net losses and ALAE paid by each succeeding year, with year 1 representing the current accident year. Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance In Year 1 2 3 4 5 6 7 8 9 10 GEICO 61.7% 19.6% 8.1% 4.9% 2.8% BHRG Property 19.0% 36.1% 18.3% 7.9% 4.3% 3.0% 1.5% 1.0% 0.2% 0.1% BHRG Casualty 10.4% 17.8% 11.5% 8.5% 7.4% 5.1% 3.0% 1.9% 1.8% 1.4% BH Primary Medical Professional Liability 1.6% 7.3% 11.5% 14.5% 14.1% 12.4% 8.4% 6.0% 4.1% 2.3% BH Primary Workers’ Compensation and Other Casualty 15.8% 21.5% 16.5% 12.0% 7.6% 4.6% 2.9% 1.5% 1.0% 0.7%
Insurance Group [Member] | GEICO [Member]
Schedule of incurred and paid losses and allocated loss adjustment expenses	GEICO’s incurred and paid losses and ALAE, net of reinsurance, are summarized by accident year below. IBNR and case development liabilities are as of December 31, 2018. Claim counts are established when accidents that may result in a liability are reported and are based on policy coverage. Each claim event may generate claims under multiple coverages, and thus may result in multiple counts. The “Cumulative Number of Reported Claims” includes the combined number of reported claims for all policy coverages and excludes projected IBNR claims. Dollars are in millions. Accident Year Incurred Losses and ALAE through December 31, IBNR and Case Cumulative 2014* 2015* 2016* 2017* 2018 2014 $ 14,680 $ 14,572 $ 14,559 $ 14,589 $ 14,651 $ 148 7,976 2015 16,887 16,875 16,993 17,039 319 8,926 2016 19,106 19,390 19,364 823 9,633 2017 22,675 22,257 2,208 10,816 2018 24,120 4,659 10,968 Incurred losses and ALAE $ 97,431 Accident Year Cumulative Paid Losses and ALAE through December 31, 2014* 2015* 2016* 2017* 2018 2014 $ 9,199 $ 12,036 $ 13,140 $ 13,850 $ 14,273 2015 10,606 13,858 15,285 16,186 2016 12,020 15,862 17,493 2017 13,878 18,249 2018 14,498 Paid losses and ALAE 80,699 Net unpaid losses and ALAE for 2014 – 2018 accident years 16,732 Net unpaid losses and ALAE for accident years before 2014 586 Net unpaid losses and ALAE $ 17,318 * Unaudited supplemental information
Property [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Schedule of incurred and paid losses and allocated loss adjustment expenses	BHRG’s disaggregated incurred and paid losses and ALAE are summarized by accident year, net of reinsurance. IBNR and case development liabilities are as of December 31, 2018. Dollars are in millions. BHRG Property Accident Year Incurred Losses and ALAE through December 31, IBNR and Case 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 2,366 $ 2,037 $ 2,232 $ 2,154 $ 2,058 $ 2,031 $ 1,990 $ 1,985 $1,984 $ 1,984 $ 7 2010 2,523 2,380 2,408 2,274 2,180 2,145 2,126 2,106 2,114 23 2011 4,300 4,084 3,810 3,720 3,719 3,689 3,666 3,652 52 2012 3,144 2,833 2,629 2,389 2,336 2,333 2,315 65 2013 3,196 3,039 2,695 2,604 2,584 2,524 105 2014 2,621 2,427 2,315 2,171 2,115 120 2015 3,244 3,088 2,531 2,938 136 2016 3,267 3,906 3,625 583 2017 5,248 4,958 600 2018 4,373 2,125 Incurred losses and ALAE $ 30,598 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 402 $ 1,110 $ 1,613 $ 1,777 $ 1,846 $ 1,916 $ 1,950 $ 1,959 $ 1,961 $ 1,963 2010 336 1,024 1,506 1,772 1,931 1,987 2,033 2,058 2,065 2011 701 2,282 2,931 3,200 3,310 3,398 3,440 3,485 2012 266 1,222 1,801 1,939 2,028 2,103 2,123 2013 516 1,427 1,866 2,063 2,184 2,264 2014 465 1,244 1,569 1,708 1,773 2015 569 1,590 1,940 2,135 2016 703 1,792 2,187 2017 1,026 2,713 2018 910 Paid losses and ALAE 21,618 Net unpaid losses and ALAE for 2009 – 2018 accident years 8,980 Net unpaid losses and ALAE for accident years before 2009 415 Net unpaid losses and ALAE $ 9,395 * Unaudited supplemental information
Casualty [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Schedule of incurred and paid losses and allocated loss adjustment expenses	BHRG Casualty Accident Year Incurred Losses and ALAE through December 31, IBNR and Case 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 2,375 $2,687 $ 2,546 $ 2,476 $ 2,414 $ 2,339 $ 2,292 $ 2,231 $2,192 $ 2,209 $ 213 2010 2,301 2,387 2,322 2,258 2,139 2,090 2,044 1,883 1,963 228 2011 2,609 2,696 2,567 2,508 2,418 2,327 2,320 2,282 363 2012 2,789 2,964 2,799 2,864 2,793 2,682 2,615 514 2013 2,130 2,259 2,290 2,134 2,082 2,028 544 2014 1,867 2,061 2,029 1,991 1,905 611 2015 1,875 2,072 2,099 2,000 647 2016 1,903 2,107 2,014 818 2017 2,189 2,676 1,141 2018 2,917 1,856 Incurred losses and ALAE $ 22,609 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 247 $ 852 $ 940 $ 1,211 $ 1,430 $ 1,586 $ 1,622 $ 1,658 $1,684 $ 1,716 2010 118 546 838 1,026 1,278 1,374 1,437 1,482 1,531 2011 292 817 1,160 1,400 1,489 1,581 1,659 1,698 2012 309 749 1,140 1,370 1,527 1,651 1,750 2013 291 521 807 935 1,039 1,140 2014 150 478 644 753 875 2015 196 491 714 834 2016 253 556 734 2017 231 568 2018 267 Paid losses and ALAE 11,113 Net unpaid losses and ALAE for 2009 – 2018 accident years 11,496 Net unpaid losses and ALAE for accident years before 2009 8,470 Net unpaid losses and ALAE $ 19,966 * Unaudited supplemental information
Medical Professional Liability [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Schedule of incurred and paid losses and allocated loss adjustment expenses	BH Primary Medical Professional Liability We estimate the ultimate expected incurred losses and loss adjustment expenses for medical professional claim liabilities using commonly accepted actuarial methodologies such as the paid and incurred development method, Bornhuetter-Ferguson based methods, hindsight outstanding severity method, trended severity method and trended pure premium method. Using a combination of these methodologies produces a range of loss estimates from which we determine our best estimate. Periodically, we study developments in older accident years and adjust initial loss estimates to reflect recent development based upon claim age, coverage and litigation experience. As previously noted, MLMIC was acquired on October 1, 2018. MLMIC’s incurred and paid losses and ALAE are included for all years presented retrospectively. Accident Year Incurred Losses and ALAE through December 31, IBNR and Cumulative 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 1,423 $ 1,349 $ 1,294 $ 1,251 $ 1,153 $ 1,060 $ 988 $ 941 $ 922 $ 904 $ 22 13 2010 1,399 1,346 1,348 1,329 1,234 1,140 1,085 1,031 1,006 43 13 2011 1,346 1,334 1,321 1,262 1,173 1,115 1,050 1,004 71 13 2012 1,336 1,306 1,277 1,223 1,168 1,078 1,035 108 13 2013 1,328 1,296 1,261 1,195 1,127 1,086 160 12 2014 1,370 1,375 1,305 1,246 1,218 296 13 2015 1,374 1,342 1,269 1,290 450 14 2016 1,392 1,416 1,414 641 14 2017 1,466 1,499 1,011 18 2018 1,602 1,410 15 Incurred losses and ALAE $ 12,058 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 5 $ 90 $ 203 $ 350 $ 480 $ 619 $ 699 $ 753 $ 789 $ 810 2010 15 95 224 377 526 654 745 810 853 2011 16 82 200 356 517 632 711 767 2012 15 93 218 377 522 642 725 2013 15 90 219 368 518 635 2014 21 106 238 396 540 2015 23 108 218 382 2016 22 115 274 2017 27 128 2018 35 Paid losses and ALAE 5,149 Net unpaid losses and ALAE for 2009 – 2018 accident years 6,909 Net unpaid losses and ALAE for accident years before 2009 379 Net unpaid losses and ALAE $ 7,288 * Unaudited supplemental information
Workers' Compensation and Other Casualty [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Schedule of incurred and paid losses and allocated loss adjustment expenses	BH Primary Workers’ Compensation and Other Casualty We periodically evaluate ultimate loss and loss adjustment expense estimates for the workers’ compensation and other casualty claims using a combination of commonly accepted actuarial methodologies such as the Bornhuetter-Ferguson and chain-ladder approaches using paid and incurred loss data. Paid and incurred loss data is segregated and analyzed by state due to the different state regulatory frameworks that may impact certain factors including the duration and amount of loss payments. We also separately study the various components of liabilities, such employee lost wages, medical expenses and the costs of claims investigations and administration. We establish case liabilities for reported claims based upon the facts and circumstances of the claim. The excess of the ultimate projected losses, including the expected development of case estimates, and the case-basis liabilities is included in IBNR liabilities. Accident Year Incurred Losses and ALAE through December 31, IBNR and Cumulative 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 732 $ 673 $ 676 $ 632 $ 609 $ 595 $ 589 $ 585 $ 576 $ 562 $ 40 46 2010 715 675 644 609 589 584 576 562 553 42 47 2011 786 706 709 657 653 647 632 622 72 51 2012 907 887 876 828 815 792 779 105 63 2013 1,339 1,310 1,257 1,210 1,173 1,148 188 83 2014 1,866 1,737 1,716 1,641 1,572 287 112 2015 2,314 2,244 2,156 2,124 445 133 2016 2,656 2,561 2,475 833 127 2017 3,262 3,122 1,395 143 2018 3,761 2,459 142 Incurred losses and ALAE $ 16,718 Accident Year Cumulative Paid Losses and ALAE through December 31, 2009* 2010* 2011* 2012* 2013* 2014* 2015* 2016* 2017* 2018 2009 $ 99 $ 228 $ 328 $ 389 $ 434 $ 464 $ 488 $ 499 $ 503 $ 507 2010 106 250 327 393 437 465 479 484 491 2011 114 222 344 415 470 498 512 522 2012 101 301 422 515 576 607 627 2013 193 452 650 776 842 887 2014 247 581 837 1,046 1,155 2015 297 715 1,044 1,328 2016 332 792 1,181 2017 467 1,078 2018 570 Paid losses and ALAE 8,346 Net unpaid losses and ALAE for 2009 – 2018 accident years 8,372 Net unpaid losses and ALAE for accident years before 2009 322 Net unpaid losses and ALAE $ 8,694 * Unaudited supplemental information

Retroactive reinsurance contr_2

Retroactive reinsurance contracts (Tables)	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Reconciliation of changes in retroactive reinsurance claim liabilities and deferred charge assets	Reconciliations of the changes in estimated liabilities for retroactive reinsurance unpaid losses and loss adjustment expenses (“claim liabilities”) and related deferred charge reinsurance assumed assets for each of the three years ended December 31, 2018 follows (in millions). 2018 2017 2016 Unpaid losses Deferred Unpaid losses Deferred Unpaid losses Deferred Balances – beginning of year $ 42,937 $ (15,278) $ 24,972 $ (8,047) $ 24,058 $ (7,687) Incurred losses and loss adjustment expenses Current year contracts 603 (86) 19,005 (7,730) 2,136 (874) Prior years’ contracts (341) 1,260 (41) 499 (63) 514 Total 262 1,174 18,964 (7,231) 2,073 (360) Paid losses and loss adjustment expenses (1,365) — (999) — (1,159) — Balances – end of year $ 41,834 $ (14,104) $ 42,937 $ (15,278) $ 24,972 $ (8,047) Incurred losses and loss adjustment expenses, net of deferred charges $ 1,436 $ 11,733 $ 1,713

Notes payable and other borro_2

Notes payable and other borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Debt principal payments disclosure	Debt principal repayments expected during each of the next five years are as follows (in millions). 2019 2020 2021 2022 2023 Insurance and other $ 6,760 $ 2,811 $ 3,261 $ 1,616 $ 5,371 Railroad, utilities and energy 5,452 2,778 2,260 3,346 4,066 $ 12,212 $ 5,589 $ 5,521 $ 4,962 $ 9,437
Insurance and Other [Member]
Schedule of short and long term outstanding debt disclosure	Notes payable and other borrowings are summarized below (in millions). The weighted average interest rates and maturity date ranges shown in the following tables are based on borrowings as of December 31, 2018. Weighted December 31, 2018 2017 Insurance and other: Berkshire Hathaway Inc. (“Berkshire”): U.S. Dollar denominated borrowings due 2019-2047 3.1% $ 9,065 $ 10,603 Euro denominated borrowings due 2020-2035 1.1% 7,806 8,164 Berkshire Hathaway Finance Corporation (“BHFC”) due 2019-2048 3.4% 10,650 12,926 Subsidiary borrowings due 2019-2045 4.0% 5,597 6,884 Short-term subsidiary borrowings 4.3% 1,857 1,832 $ 34,975 $ 40,409
Railroad, Utilities and Energy [Member]
Schedule of short and long term outstanding debt disclosure	Weighted December 31, 2018 2017 Railroad, utilities and energy: Berkshire Hathaway Energy Company (“BHE”) and subsidiaries: BHE senior unsecured debt due 2020-2049 4.6 % $ 8,577 $ 6,452 Subsidiary and other debt due 2019-2064 4.7 % 28,196 28,739 Short-term debt 3.1 % 2,516 4,488 Burlington Northern Santa Fe and subsidiaries due 2019-2097 4.7 % 23,226 22,499 $ 62,515 $ 62,178

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of income tax liability	The liabilities for income taxes reflected in our Consolidated Balance Sheets are as follows (in millions). December 31, 2018 2017 Currently payable (receivable) $ 323 $ (129) Deferred 50,503 56,182 Other 549 554 $ 51,375 $ 56,607
Schedule of deferred tax assets and liabilities	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and deferred tax liabilities are shown below (in millions). December 31, 2018 2017 Deferred tax liabilities: Investments – unrealized appreciation and cost basis differences $ 17,765 $ 24,251 Deferred charges reinsurance assumed 2,970 3,226 Property, plant and equipment 28,279 26,671 Goodwill and other intangible assets 7,199 7,204 Other 3,187 3,216 59,400 64,568 Deferred tax assets: Unpaid losses and loss adjustment expenses (1,238) (1,231) Unearned premiums (767) (345) Accrued liabilities (1,956) (2,501) Regulatory liabilities (1,673) (1,707) Other (3,263) (2,602) (8,897) (8,386) Net deferred tax liability $ 50,503 $ 56,182
Schedule of tax provision by jurisdiction category and classification	Income tax expense reflected in our Consolidated Statements of Earnings for each of the three years ending December 31, 2018 is as follows (in millions). 2018 2017 2016 Federal $ (1,613) $ (23,427) $ 7,796 State 175 894 556 Foreign 1,117 1,018 888 $ (321) $ (21,515) $ 9,240 Current $ 5,176 $ 3,299 $ 6,565 Deferred (5,497) (24,814) 2,675 $ (321) $ (21,515) $ 9,240
Schedule of income tax reconciled to federal statutory amount	Income tax expense is reconciled to hypothetical amounts computed at the U.S. federal statutory rate for each of the three years ending December 31, 2018 in the table below (in millions). 2018 2017 2016 Earnings before income taxes $ 4,001 $ 23,838 $ 33,667 Hypothetical income tax expense computed at the U.S. federal statutory rate $ 840 $ 8,343 $ 11,783 Dividends received deduction and tax exempt interest (393) (905 ) (789 ) State income taxes, less U.S. federal income tax benefit 138 465 361 Foreign tax rate differences 271 (339 ) (421 ) U.S. income tax credits (711) (636 ) (518 ) Non-taxable — — (1,143 ) Net benefit from the enactment of the TCJA (302) (28,200 ) — Other differences, net (164) (243 ) (33 ) $ (321) $ (21,515 ) $ 9,240

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	Our financial assets and liabilities are summarized below as of December 31, 2018 and December 31, 2017, with fair values shown according to the fair value hierarchy (in millions). The carrying values of cash and cash equivalents, U.S. Treasury Bills, receivables and accounts payable, accruals and other liabilities are considered to be reasonable estimates of their fair values. Carrying Fair Value Quoted Significant Other Significant December 31, 2018 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 4,223 $ 4,223 $ 2,933 $ 1,290 $ — States, municipalities and political subdivisions 189 189 — 189 — Foreign governments 7,502 7,502 5,417 2,085 — Corporate bonds 7,440 7,440 — 7,434 6 Mortgage-backed securities 544 544 — 544 — Investments in equity securities 172,757 172,757 172,253 203 301 Investment in Kraft Heinz common stock 13,813 14,007 14,007 — — Loans and finance receivables 16,280 16,377 — 1,531 14,846 Derivative contract assets (1) 172 172 2 52 118 Derivative contract liabilities: Railroad, utilities and energy (1) 111 111 1 101 9 Equity index put options 2,452 2,452 — — 2,452 Notes payable and other borrowings: Insurance and other 34,975 35,361 — 35,335 26 Railroad, utilities and energy 62,515 66,422 — 66,422 — December 31, 2017 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 3,953 $ 3,953 $ 2,360 $ 1,593 $ — States, municipalities and political subdivisions 854 854 — 854 — Foreign governments 8,822 8,822 6,946 1,876 — Corporate bonds 6,862 6,862 — 6,856 6 Mortgage-backed securities 862 862 — 862 — Investments in equity securities 170,540 170,540 170,494 46 — Investment in Kraft Heinz common stock 17,635 25,306 25,306 — — Loans and finance receivables 13,748 14,136 — 17 14,119 Derivative contract assets (1) 142 142 1 28 113 Derivative contract liabilities: Railroad, utilities and energy (1) 82 82 3 69 10 Equity index put options 2,172 2,172 — — 2,172 Notes payable and other borrowings: Insurance and other 40,409 41,762 — 41,757 5 Railroad, utilities and energy 62,178 70,538 — 70,538 — (1) Assets are included in other assets and liabilities are included in accounts payable, accruals and other liabilities.
Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3)	Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) for each of the three years ending December 31, 2018 follow (in millions). Investments Net Balance December 31, 2015 $ 21,503 $ (3,785 ) Gains (losses) included in: Earnings 3,593 880 Other comprehensive income 872 (2 ) Regulatory assets and liabilities — (11 ) Acquisitions 10 — Dispositions and settlements (8,656 ) (101 ) Transfers into/out of Level 3 (1 ) 195 Balance December 31, 2016 17,321 (2,824 ) Gains (losses) included in: Earnings — 888 Other comprehensive income 1,157 (3 ) Regulatory assets and liabilities — (1 ) Dispositions and settlements (59 ) (129 ) Transfers into/out of Level 3 (18,413 ) — Balance December 31, 2017 6 (2,069 ) Gains (losses) included in: Earnings — (118 ) Other comprehensive income — 2 Regulatory assets and liabilities — 3 Acquisitions 302 3 Dispositions and settlements (1 ) (164 ) Balance December 31, 2018 $ 307 $ (2,343 )
Fair value assets and liabilities measured on recurring basis, unobservable inputs, additional information	Quantitative information as of December 31, 2018, with respect to assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) follows (in millions). Fair Principal Valuation Unobservable Inputs Weighted Derivative contract liabilities – Equity index put options $ 2,452 Option pricing model Volatility 18%

Common stock (Tables)

Common stock (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in issued, treasury and outstanding Berkshire common stock	Changes in Berkshire’s issued, treasury and outstanding common stock during the three years ending December 31, 2018 are shown in the table below. In addition to our common stock, 1,000,000 shares of preferred stock are authorized, but none are issued. Class A, $5 Par Value Class B, $0.0033 Par Value Issued Treasury Outstanding Issued Treasury Outstanding Balance December 31, 2015 820,102 (11,680 ) 808,422 1,253,866,598 (1,409,762 ) 1,252,456,836 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (32,044 ) — (32,044 ) 49,457,329 — 49,457,329 Balance December 31, 2016 788,058 (11,680) 776,378 1,303,323,927 (1,409,762 ) 1,301,914,165 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (25,303 ) — (25,303 ) 38,742,822 — 38,742,822 Balance December 31, 2017 762,755 (11,680 ) 751,075 1,342,066,749 (1,409,762 ) 1,340,656,987 Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition (20,542 ) — (20,542 ) 31,492,234 — 31,492,234 Treasury stock acquired — (1,217 ) (1,217 ) — (4,729,147 ) (4,729,147 ) Balance at December 31, 2018 742,213 (12,897 ) 729,316 1,373,558,983 (6,138,909 ) 1,367,420,074

Accumulated other comprehensi_2

Accumulated other comprehensive income (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Schedule of accumulated other comprehensive income	A summary of the net changes in after-tax Unrealized Foreign Prior service Other Accumulated Balance December 31, 2015 $ 38,598 $ (3,856) $ (762 ) $ 2 $ 33,982 Other comprehensive income, net before reclassifications 9,011 (1,412) 94 (48 ) 7,645 Reclassifications into net earnings: Earnings before income taxes (6,820) — 104 51 (6,665) Applicable income taxes 2,387 — (29 ) (22 ) 2,336 Balance December 31, 2016 43,176 (5,268) (593 ) (17 ) 37,298 Other comprehensive income, net before reclassifications 19,826 2,151 65 16 22,058 Reclassifications into net earnings: Reclassifications before income taxes (1,399) 3 155 19 (1,222) Applicable income taxes 490 — (47 ) (6 ) 437 Balance December 31, 2017 62,093 (3,114) (420 ) 12 58,571 Reclassifications to retained earnings upon adoption of new accounting standards (61,340) (65) 36 (6 ) (61,375) Other comprehensive income, net before reclassifications (183) (1,424) (513 ) 25 (2,095) Reclassifications into net earnings: Reclassifications before income taxes (253) — 116 5 (132) Applicable income taxes 53 — (35 ) (2 ) 16 Balance December 31, 2018 $ 370 $ (4,603) $ (816 ) $ 34 $ (5,015)

Revenues from contracts with _2

Revenues from contracts with customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from contracts with customers disaggregated by reportable segment and source of revenue	The following table summarizes customer contract revenues disaggregated by reportable segment and the source of the revenue for the year ended December 31, 2018 (in millions). Other revenues included in our consolidated revenues were primarily insurance premiums earned, interest, dividend and other investment income and leasing revenues which are not within the scope of ASC 606. Manufacturing McLane Service and BNSF Berkshire Insurance, Total Manufactured products: Industrial and commercial products $ 25,707 $ — $ 204 $ — $ — $ — $ 25,911 Building products 14,323 — — — — — 14,323 Consumer products 14,790 — — — — — 14,790 Grocery and convenience store distribution — 33,518 — — — — 33,518 Food and beverage distribution — 16,309 — — — — 16,309 Auto sales — — 8,181 — — — 8,181 Other retail and wholesale distribution 2,091 — 12,067 — — — 14,158 Service 1,519 84 4,100 23,652 3,949 — 33,304 Electricity and natural gas — — — — 14,951 — 14,951 Total 58,430 49,911 24,552 23,652 18,900 — 175,445 Other revenue 3,340 76 4,297 51 1,070 63,558 72,392 $ 61,770 $ 49,987 $ 28,849 $ 23,703 $ 19,970 $ 63,558 $ 247,837
Transaction price allocated to significant unsatisfied remaining performance obligations	A summary of the transaction price allocated to the significant unsatisfied remaining performance obligations relating to contracts with expected durations in excess of one year as of December 31, 2018 follows (in millions). Performance obligations expected to be satisfied: Less than Greater than Total Electricity and natural gas $ 842 $ 5,678 $ 6,520 Other sales and service contracts 1,190 1,904 3,094

Pension plans (Tables)

Pension plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Schedule of net periodic pension expense	The components of our net periodic pension expense for each of the three years ending December 31, 2018 were as follows (in millions). 2018 2017 2016 Service cost $ 271 $ 273 $ 282 Interest cost 593 635 691 Expected return on plan assets (988 ) (939 ) (908 ) Amortization of actuarial losses and other 188 157 148 Net periodic pension expense $ 64 $ 126 $ 213
Schedule of changes in projected benefit obligations, changes in plan assets and net funded status	Reconciliations of the changes in plan assets and PBOs related to BHE’s pension plans and all other pension plans for each of the two years ending December 31, 2018 are in the following tables (in millions). The costs of pension plans covering employees of certain regulated subsidiaries of BHE are generally recoverable through the regulated rate making process. 2018 2017 BHE All other Consolidated BHE All other Consolidated Benefit obligations Accumulated benefit obligation end of year $ 4,346 $ 11,540 $ 15,886 $ 4,920 $ 12,604 $ 17,524 PBO beginning of year $ 5,207 $ 13,617 $ 18,824 $ 5,077 $ 12,673 $ 17,750 Service cost 40 231 271 47 226 273 Interest cost 161 432 593 174 461 635 Benefits paid (208 ) (633 ) (841) (271 ) (626 ) (897 ) Settlements (301 ) (133 ) (434) (146 ) (95 ) (241 ) Actuarial (gains) or losses and other (348 ) (1,143 ) (1,491) 326 978 1,304 PBO end of year $ 4,551 $ 12,371 $ 16,922 $ 5,207 $ 13,617 $ 18,824 Plan assets Plan assets beginning of year $ 5,129 $ 11,885 $ 17,014 $ 4,694 $ 10,703 $ 15,397 Employer contributions 98 495 593 122 159 281 Benefits paid (208 ) (633 ) (841) (271 ) (626 ) (897 ) Actual return on plan assets (191 ) (949 ) (1,140) 535 1,601 2,136 Settlements (324 ) (132 ) (456) (159 ) (76 ) (235 ) Other (119 ) (92 ) (211) 208 124 332 Plan assets end of year $ 4,385 $ 10,574 $ 14,959 $ 5,129 $ 11,885 $ 17,014 Funded status – net liability $ 166 $ 1,797 $ 1,963 $ 78 $ 1,732 $ 1,810
Schedule of weighted average assumptions	Weighted average assumptions used in determining PBO and net periodic pension expense were as follows. 2018 2017 2016 Discount rate applicable to pension benefit obligations 3.9% 3.3% 3.8% Expected long-term rate of return on plan assets 6.4 6.4 6.1 Rate of compensation increase 2.6 2.8 3.0 Discount rate applicable to net periodic pension expense 3.4 3.9 4.2
Schedule of fair value measurements by major categories of plan assets	Fair value measurements of plan assets as of December 31, 2018 and 2017 follow (in millions). Fair Value Investment funds Total Level 1 Level 2 Level 3 December 31, 2018 Cash and cash equivalents $ 1,328 $ 1,197 $ 131 $ — $ — Equity securities 7,671 7,499 22 150 — Government obligations 1,727 1,654 73 — — Other fixed maturity securities 836 172 631 33 — Investment funds and other 3,397 170 1,042 273 1,912 $ 14,959 $ 10,692 $ 1,899 $ 456 $ 1,912 December 31, 2017 Cash and cash equivalents $ 738 $ 594 $ 144 $ — $ — Equity securities 9,824 9,641 23 160 — Government obligations 1,536 1,497 39 — — Other fixed maturity securities 799 148 619 32 — Investment funds and other 4,117 150 1,501 274 2,192 $ 17,014 $ 12,030 $ 2,326 $ 466 $ 2,192
Schedule of pension plan amounts recognized In accumulated other comprehensive income	A reconciliation of the pre-tax 2018 2017 Balance beginning of year $ (614 ) $ (839 ) Amount included in net periodic pension expense 116 155 Actuarial gains (losses) and other (686 ) 70 Balance end of year $ (1,184 ) $ (614 )

Contingencies and Commitments (

Contingencies and Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of minimum rental payments for operating leases	Future minimum rental payments for operating leases having non-cancellable 2019 2020 2021 2022 2023 After 2023 Total $1,360 $1,317 $1,098 $872 $708 $3,658 $9,013

Business segment data (Tables)

Business segment data (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of revenues, earnings before income taxes, interest expense, income tax expense, capital expenditures, depreciation, goodwill and identifiable assets by segment	A disaggregation of our consolidated data for each of the three most recent years is presented in the tables which follow (in millions). Revenues Earnings before income taxes 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance: Underwriting: GEICO $ 33,363 $ 29,441 $ 25,483 $ 2,449 $ (310 ) $ 462 Berkshire Hathaway Reinsurance Group 15,944 24,013 14,141 (1,109 ) (3,648 ) 1,012 Berkshire Hathaway Primary Group 8,111 7,143 6,257 670 719 657 Insurance underwriting 57,418 60,597 45,881 2,010 (3,239 ) 2,131 Investment income 5,518 4,865 4,522 5,503 4,855 4,482 Total insurance 62,936 65,462 50,403 7,513 1,616 6,613 BNSF 23,855 21,387 19,829 6,863 6,328 5,693 Berkshire Hathaway Energy 19,987 18,854 17,764 2,472 2,499 2,878 Manufacturing 61,883 57,645 52,969 9,366 8,324 7,735 McLane Company 49,987 49,775 48,075 246 299 431 Service and retailing 28,939 27,219 26,392 2,696 2,304 2,058 247,587 240,342 215,432 29,156 21,370 25,408 Reconciliation to consolidated amount: Investment and derivative gains/losses — — — (22,455 ) 2,128 8,304 Interest expense, not allocated to segments — — — (458 ) (486 ) (474 ) Equity method investments — — — (2,167 ) 3,014 1,109 Corporate, eliminations and other 250 (409 ) (318 ) (75 ) (2,188 ) (680 ) $ 247,837 $ 239,933 $ 215,114 $ 4,001 $ 23,838 $ 33,667 Interest expense Income tax expense 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ — $ — $ — $ 1,374 $ (71 ) $ 1,585 BNSF 1,041 1,016 992 1,644 2,369 2,124 Berkshire Hathaway Energy 1,777 2,254 1,715 (452 ) 148 371 Manufacturing 690 679 631 2,188 2,678 2,442 McLane Company 15 19 — 59 94 169 Service and retailing 91 67 71 634 812 761 3,614 4,035 3,409 5,447 6,030 7,452 Reconciliation to consolidated amount: Investment and derivative gains/losses — — — (4,673 ) 742 1,807 Interest expense, not allocated to segments 458 486 474 (96 ) (170 ) (166) Equity method investments — — — (753 ) 910 396 Income tax net benefit – Tax Cuts and Jobs Act of 2017 — — — — (28,200 ) — Corporate, eliminations and other (219) (135 ) (142 ) (246 ) (827 ) (249) $ 3,853 $ 4,386 $ 3,741 $ (321 ) $ (21,515 ) $ 9,240 Capital expenditures Depreciation of tangible assets 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ 130 $ 170 $ 128 $ 79 $ 84 $ 85 BNSF 3,187 3,256 3,819 2,268 2,304 2,079 Berkshire Hathaway Energy 6,241 4,571 5,090 2,830 2,548 2,560 Manufacturing 3,116 2,490 2,581 1,890 1,839 1,757 McLane Company 276 289 258 204 193 165 Service and retailing 1,587 932 1,078 1,115 751 765 $ 14,537 $ 11,708 $ 12,954 $ 8,386 $ 7,719 $ 7,411 Goodwill year-end Identifiable assets year-end 2018 2017 2016 2018 2017 2016 Operating Businesses: Insurance $ 15,289 $ 15,499 $ 15,474 $ 289,746 $ 294,418 $ 234,037 BNSF 14,851 14,845 14,845 70,242 69,438 69,277 Berkshire Hathaway Energy 9,851 9,935 9,266 80,543 77,710 74,571 Manufacturing 34,019 33,967 32,915 99,912 97,753 93,835 McLane Company 734 734 734 6,243 6,090 5,896 Service and retailing 6,281 6,278 6,252 24,724 20,014 19,208 $ 81,025 $ 81,258 $ 79,486 571,410 565,423 496,824 Reconciliation to consolidated amount: Corporate and other 55,359 55,414 44,544 Goodwill 81,025 81,258 79,486 $ 707,794 $ 702,095 $ 620,854
Schedule of premiums written and earned	Premiums written and earned by the property/casualty and life/health insurance businesses are summarized below (in millions). Property/Casualty Life/Health 2018 2017 2016 2018 2017 2016 Premiums Written: Direct $ 44,513 $ 39,377 $ 34,001 $ 1,111 $ 866 $ 1,060 Assumed 8,970 17,815 8,037 5,540 4,925 4,672 Ceded (869 ) (694 ) (798 ) (49 ) (47 ) (62 ) $ 52,614 $ 56,498 $ 41,240 $ 6,602 $ 5,744 $ 5,670 Premiums Earned: Direct $ 43,095 $ 37,755 $ 33,207 $ 1,111 $ 866 $ 1,060 Assumed 8,649 17,813 7,848 5,438 4,866 4,671 Ceded (825 ) (677 ) (843 ) (50 ) (26 ) (62 ) $ 50,919 $ 54,891 $ 40,212 $ 6,499 $ 5,706 $ 5,669
Schedule of insurance premiums written by geographic region	Insurance premiums written by geographic region (based upon the domicile of the insured or reinsured) are summarized below. Dollars are in millions. Property/Casualty Life/Health 2018 2017 2016 2018 2017 2016 United States $ 46,146 $ 50,604 $ 35,878 $ 3,598 $ 3,320 $ 3,473 Asia Pacific 3,726 3,307 3,616 1,361 879 715 Western Europe 2,157 1,516 1,406 939 909 822 All other 585 1,071 340 704 636 660 $ 52,614 $ 56,498 $ 41,240 $ 6,602 $ 5,744 $ 5,670

Quarterly data (Tables)

Quarterly data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly revenues and earnings	A summary of revenues and net earnings by quarter for each of the last two years follows. This information is unaudited. Amounts are in millions, except per share amounts. 1 st 2 nd 3 rd 4 th 2018 Revenues $ 58,473 $ 62,200 $ 63,450 $ 63,714 Net earnings (loss) attributable to Berkshire shareholders * (1,138 ) 12,011 18,540 (25,392 ) Net earnings (loss) attributable to Berkshire shareholders per equivalent Class A common share (692 ) 7,301 11,280 (15,467 ) 2017 Revenues $ 64,370 $ 57,256 $ 59,507 $ 58,800 Net earnings attributable to Berkshire shareholders * 4,060 4,262 4,067 32,551 Net earnings attributable to Berkshire shareholders per equivalent Class A common share 2,469 2,592 2,473 19,790 * Includes after-tax one-time 1 st 2 nd 3 rd 4 th Investment and derivative gains/losses – 2018 $ (6,426 ) $ 5,118 $ 11,660 $ (28,089 ) Investment and derivative gains/losses – 2017 504 143 623 107 Income tax net benefit – Tax Cuts and Jobs Act of 2017 — — — 28,200

Significant accounting polici_4

Significant accounting policies and practices - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Percentage of LIFO inventory	39.00%
Excess of current or replacement costs over costs determined under LIFO	$ 1,000
Minimum [Member]
Significant Accounting Policies [Line Items]
Insurance interest rate assumption	1.00%
Maximum [Member]
Significant Accounting Policies [Line Items]
Insurance interest rate assumption	7.00%
Insurance and Other [Member]
Significant Accounting Policies [Line Items]
Equipment held for lease	$ 14,298			$ 10,167
Aircraft repurchase liabilities and unearned lease revenues	$ 4,593
Buildings and improvements [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	5 years
Buildings and improvements [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	50 years
Machinery and equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Machinery and equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	25 years
Furniture, fixtures and other [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Furniture, fixtures and other [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	15 years
Track structure and other roadway [Member] | Railroad [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	9 years
Track structure and other roadway [Member] | Railroad [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	100 years
Locomotives, freight cars and other equipment [Member] | Railroad [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	6 years
Locomotives, freight cars and other equipment [Member] | Railroad [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	41 years
Utility generation, transmission and distribution systems [Member] | Utilities and Energy [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	5 years
Utility generation, transmission and distribution systems [Member] | Utilities and Energy [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	80 years
Interstate natural gas pipeline assets [Member] | Utilities and Energy [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Interstate natural gas pipeline assets [Member] | Utilities and Energy [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	80 years
Independent power plants and other assets [Member] | Utilities and Energy [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Independent power plants and other assets [Member] | Utilities and Energy [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	30 years
Equipment held for lease [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	6 years
Equipment held for lease [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life (in years)	35 years
Other Assets [Member]
Significant Accounting Policies [Line Items]
Unamortized balances of deferred policy acquisition costs	$ 2,658			$ 2,529
Aircraft Sold Under Fractional Aircraft Ownership Programs [Member] | ASC 606 [Member] | Insurance and Other [Member]
Significant Accounting Policies [Line Items]
Equipment held for lease			$ 3,500
Aircraft repurchase liabilities and unearned lease revenues			$ 3,500
Subsequent Event [Member] | ASU 2016-02 [Member]
Significant Accounting Policies [Line Items]
Operating leases, right of use assets		$ 6,000
Operating lease liabilities		$ 6,000

Summary of effects of initial a

Summary of effects of initial adoption of ASU 2016-01, ASU 2018-02 and ASC 606 (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets	$ 707,794	$ 702,095	$ 620,854
Liabilities	355,294	350,141
Accumulated other comprehensive income	(5,015)	58,571
Retained earnings	321,112	255,786
Total shareholders' equity	352,500	$ 351,954	$ 285,428	$ 257,696
ASU 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated other comprehensive income	84
Retained earnings	(84)
ASC 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets	3,382
Liabilities	3,453
Retained earnings	(70)
Total shareholders' equity	(70)
ASU 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated other comprehensive income	(61,459)
Retained earnings	61,459
Adjustments for New Accounting Pronouncements [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets	3,382
Liabilities	3,453
Accumulated other comprehensive income	(61,375)
Retained earnings	61,305
Total shareholders' equity	$ (70)

Significant business acquisit_3

Significant business acquisitions - Narrative (Detail) - USD ($) $ in Millions	Oct. 01, 2018	Feb. 29, 2016	Jan. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Fair value of shares exchanged						$ 4,239
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Aggregate consideration paid for acquisitions				$ 1,000	$ 2,700	$ 1,400
Precision Castparts Corp. [Member]
Business Acquisition [Line Items]
Acquisition price			$ 32,700
Assets			47,899
Cash			250
Liabilities			$ 15,241
MLMIC Insurance Company [Member]
Business Acquisition [Line Items]
Premiums earned				$ 400
MLMIC Insurance Company [Member] | NICO [Member]
Business Acquisition [Line Items]
Acquisition price	$ 2,500
Assets	6,100
Cash	230
Investments	5,200
Liabilities	3,600
Unpaid losses and loss adjustment expenses	$ 3,200
Duracell Company [Member]
Business Acquisition [Line Items]
Assets		$ 5,143
Cash		1,807
Liabilities		904
Procter & Gamble Company [Member] | Duracell Company [Member]
Business Acquisition [Line Items]
Fair value of shares exchanged		$ 4,239

Significant business acquisit_4

Significant business acquisitions - Estimated fair values of assets acquired and liabilities assumed (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 29, 2016	Jan. 29, 2016
Business Acquisition [Line Items]
Goodwill	$ 81,025	$ 81,258	$ 79,486
Precision Castparts Corp. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents					$ 250
Inventories					3,430
Property, plant and equipment					2,765
Goodwill					16,011
Other intangible assets					23,527
Other assets					1,916
Assets acquired					47,899
Accounts payable, accruals and other liabilities					2,442
Notes payable and other borrowings					5,251
Income taxes, principally deferred					7,548
Liabilities assumed					15,241
Net assets					$ 32,658
Duracell Company [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 1,807
Inventories				319
Property, plant and equipment				359
Goodwill				866
Other intangible assets				1,550
Other assets				242
Assets acquired				5,143
Accounts payable, accruals and other liabilities				410
Income taxes, principally deferred				494
Liabilities assumed				904
Net assets				$ 4,239

Investments in fixed maturity_3

Investments in fixed maturity securities (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	$ 19,427	$ 20,445
Unrealized gains on fixed maturity securities	546	977
Unrealized losses on fixed maturity securities	(75)	(69)
Fair value of fixed maturity securities	19,898	21,353
U.S. Treasury, U.S. government corporations and agencies [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	4,223	3,975
Unrealized gains on fixed maturity securities	22	4
Unrealized losses on fixed maturity securities	(22)	(26)
Fair value of fixed maturity securities	4,223	3,953
States, municipalities and political subdivisions [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	182	847
Unrealized gains on fixed maturity securities	7	19
Unrealized losses on fixed maturity securities		(12)
Fair value of fixed maturity securities	189	854
Foreign governments [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	7,480	8,572
Unrealized gains on fixed maturity securities	50	274
Unrealized losses on fixed maturity securities	(28)	(24)
Fair value of fixed maturity securities	7,502	8,822
Corporate bonds [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	7,055	6,279
Unrealized gains on fixed maturity securities	408	588
Unrealized losses on fixed maturity securities	(23)	(5)
Fair value of fixed maturity securities	7,440	6,862
Mortgage-backed securities [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	487	772
Unrealized gains on fixed maturity securities	59	92
Unrealized losses on fixed maturity securities	(2)	(2)
Fair value of fixed maturity securities	$ 544	$ 862

Investments in fixed maturity_4

Investments in fixed maturity securities - Narrative (Detail)	Dec. 31, 2018
Foreign governments [Member] | AA or Higher Credit Rating [Member]
Summary of Investment Holdings [Line Items]
Percentage of fixed maturity investments by credit rating	88.00%

Investments in fixed maturity_5

Investments in fixed maturity securities - Amortized cost and estimated fair value of securities with fixed maturities (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Due in one year or less - amortized cost	$ 6,973
Due after one year through five years - amortized cost	10,937
Due after five years through ten years - amortized cost	438
Due after ten years - amortized cost	592
Amortized cost of fixed maturity securities	19,427	$ 20,445
Due in one year or less - fair value	6,982
Due after one year through five years - fair value	10,994
Due after five years through ten years - fair value	494
Due after ten years - fair value	884
Fair value of fixed maturity securities	19,898	21,353
Mortgage-backed securities [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of mortgage-backed securities	487
Amortized cost of fixed maturity securities	487	772
Fair value of mortgage-backed securities	544
Fair value of fixed maturity securities	$ 544	$ 862

Investments in equity securit_3

Investments in equity securities (Detail) - USD ($) $ in Millions	Dec. 31, 2018		Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Cost Basis	$ 102,867		$ 74,676
Net Unrealized Gains	69,890		95,864
Fair Value	172,757	[1]	170,540	[2]
Banks, insurance and finance [Member]
Summary of Investment Holdings [Line Items]
Cost Basis	44,332		25,783
Net Unrealized Gains	38,260		55,026
Fair Value	82,592		80,809
Consumer products [Member]
Summary of Investment Holdings [Line Items]
Cost Basis	38,783		25,177
Net Unrealized Gains	22,838		25,698
Fair Value	61,621		50,875
Commercial, industrial and other [Member]
Summary of Investment Holdings [Line Items]
Cost Basis	19,752		23,716
Net Unrealized Gains	8,792		15,140
Fair Value	$ 28,544		$ 38,856
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.5 billion; Apple Inc. - $40.3 billion; Bank of America Corporation - $22.6 billion; The Coca-Cola Company - $18.9 billion and Wells Fargo & Company - $20.7 billion).
[2]	Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company - $15.1 billion; Apple Inc. - $28.2 billion; Bank of America Corporation - $20.7 billion; The Coca-Cola Company - $18.4 billion and Wells Fargo & Company - $29.3 billion).

Investments in equity securit_4

Investments in equity securities (Parenthetical) (Detail) $ in Millions	Dec. 31, 2018USD ($)Company		Dec. 31, 2017USD ($)Company
Summary of Investment Holdings [Line Items]
Fair value of investments	$ 172,757	[1]	$ 170,540	[2]
American Express Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	14,500		15,100
Apple Inc. [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	40,300		28,200
Bank of America Corporation [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	22,600		20,700
The Coca-Cola Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	18,900		18,400
Wells Fargo & Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	$ 20,700		$ 29,300
Equity Securities [Member] | Investment Concentration [Member]
Summary of Investment Holdings [Line Items]
Concentration percentage	68.00%		65.00%
Number of companies in concentration percentage | Company	5		5
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.5 billion; Apple Inc. - $40.3 billion; Bank of America Corporation - $22.6 billion; The Coca-Cola Company - $18.9 billion and Wells Fargo & Company - $20.7 billion).
[2]	Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company - $15.1 billion; Apple Inc. - $28.2 billion; Bank of America Corporation - $20.7 billion; The Coca-Cola Company - $18.4 billion and Wells Fargo & Company - $29.3 billion).

Investments in equity securit_5

Investments in equity securities - Narrative (Detail) - Bank of America Corporation [Member] - USD ($)	Aug. 24, 2017	Dec. 31, 2011
Non-Cumulative Perpetual Preferred Stock [Member]
Summary of Investment Holdings [Line Items]
Number of shares acquired		50,000
Investment in preferred stock, stated dividend rate		6.00%
Investment in preferred stock, liquidation value per share		$ 100,000
Common Stock [Member]
Summary of Investment Holdings [Line Items]
Number of common shares that can be purchased		700,000,000
Exercise price for warrants, per share		$ 7.142857
Aggregate cost to exercise warrants	$ 5,000,000,000	$ 5,000,000,000
Number of shares acquired upon exercise of warrants	700,000,000

Equity method investments - Nar

Equity method investments - Narrative (Detail)	Oct. 03, 2017USD ($)EmployeeLocation	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Equity method earnings (losses)		$ (2,167,000,000)	$ 3,014,000,000	$ 1,109,000,000
The Kraft Heinz Company [Member]
Schedule of Equity Method Investments [Line Items]
Number of shares owned | shares		325,442,152
Equity method investment ownership percentage		26.70%
Equity method investments, fair value		$ 14,007,000,000	25,306,000,000
Equity method investments, carrying value		13,813,000,000	17,635,000,000
Equity method earnings (losses)		(2,730,000,000)	2,938,000,000	923,000,000
Common stock dividends received		814,000,000	797,000,000
Berkadia Commercial Mortgage LLC, Pilot Travel Centers LLC, d/b/a Pilot Flying J, and Electric Transmission Texas, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments, carrying value		3,500,000,000	3,400,000,000
Equity method earnings (losses)		$ 563,000,000	76,000,000	186,000,000
Berkadia Commercial Mortgage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Commercial paper outstanding		$ 1,470,000,000
Jefferies Financial Group Inc. [Member] | Berkadia Commercial Mortgage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
American Electric Power [Member] | Electric Transmission Texas, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Commercial Paper [Member] | Berkadia Commercial Mortgage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Maximum outstanding balance of commercial paper borrowings		$ 1,500,000,000
Insurance Group [Member] | Jefferies Financial Group Inc. [Member] | Berkadia Commercial Mortgage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Reimbursement rate from joint venture partner of Company's surety bond claim losses		50.00%
Berkshire Hathaway Energy Company Subsidiary [Member] | Electric Transmission Texas, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Berkshire Hathaway Inc. (Parent) [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments, carrying value		$ 13,813,000,000	17,635,000,000
Equity method earnings (losses)		$ (2,730,000,000)	$ 2,938,000,000	$ 923,000,000
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member]
Schedule of Equity Method Investments [Line Items]
Number of locations | Location	750
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Haslam Family [Member]
Schedule of Equity Method Investments [Line Items]
Majority ownership percentage	50.10%
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Third Party [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	11.30%
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	38.60%
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Number of team members | Employee	28,000
Annual revenues	$ 20,000,000,000
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Agreement to Acquire Additional Interest in 2023 [Member] | Haslam Family [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Agreement to Acquire Additional Interest in 2023 [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of additional interest to be acquired	41.40%

Equity method investments - Una

Equity method investments - Unaudited financial information (Detail) - The Kraft Heinz Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Assets	$ 103,627	$ 120,232
Liabilities	51,721	53,985
Sales	26,259	26,085	$ 26,335
Net earnings (losses) attributable to Kraft Heinz common shareholders	$ (10,229)	$ 10,999	$ 3,452

Investment gains_losses (Detail

Investment gains/losses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain (Loss) on Securities [Line Items]
Equity securities - Unrealized investment gains/losses on securities held at the end of the period	$ (22,729)
Equity securities - Investment gains/losses during 2018 on securities sold in 2018	291
Investment gains (losses)	(22,155)	$ 1,410	$ 7,553
Fixed maturity securities - Gross realized gains	480	103	58
Fixed maturity securities - Gross realized losses	(227)	(22)	(51)
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Gross realized gains		2,237	7,853
Gross realized losses		(919)	(415)
Investment gains (losses)	(22,438)	1,318	7,438
Other [Member]
Gain (Loss) on Securities [Line Items]
Investment gains (losses)	$ 30	$ 11	$ 108

Investment gains_losses - Narra

Investment gains/losses - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain (Loss) on Securities [Line Items]
Sales and redemptions of equity securities	$ 18,783	$ 19,512	$ 28,464
Taxable gains on sales of equity securities	3,300
Investment gains (losses)	$ (22,155)	1,410	7,553
Bank of America Corporation [Member] | Non-Cumulative Perpetual Preferred Stock [Member]
Gain (Loss) on Securities [Line Items]
Investment gains (losses)		$ 1,000
Wm Wrigley Jr Company, The Kraft Heinz Company, and Dow Chemical Company [Member] | Preferred Stock and Common Stock [Member]
Gain (Loss) on Securities [Line Items]
Gross gains			4,200
Duracell Company [Member] | Procter & Gamble Company [Member] | Common Stock [Member]
Gain (Loss) on Securities [Line Items]
Gross gains			$ 1,100

Loans and finance receivables_2

Loans and finance receivables (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Loans and finance receivables before allowances and discounts	$ 16,622	$ 14,126
Allowances for uncollectible loans	(177)	(180)
Unamortized acquisition discounts	(165)	(198)
Loans and finance receivables	$ 16,280	$ 13,748

Loans and finance receivables -

Loans and finance receivables - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Loans and Finance Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provisions for loan losses	$ 141,000,000	$ 160,000,000
Loan charge-offs, net of recoveries	$ 144,000,000	$ 162,000,000
Percent of manufactured housing loan balances evaluated collectively for impairment	98.00%
Percent of loan balances considered to be performing	99.00%
Percent of loan balances considered to be current as to payment status	95.00%
Seritage Growth Properties [Member] | Term Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loan facility amount	$ 2,000,000,000
Expiration date of term loan	Jul. 31, 2023
Outstanding loan balance	$ 1,600,000,000

Other receivables (Detail)

Other receivables (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reinsurance recoverable on unpaid losses	$ 3,060	$ 3,201	$ 3,338	$ 3,307
Insurance and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Insurance premiums receivable	12,452	11,058
Reinsurance recoverable on unpaid losses	3,060	3,201
Trade receivables	12,617	12,031
Other	3,823	3,464
Allowances for uncollectible accounts	(388)	(362)
Other receivables	31,564	29,392
Railroad, Utilities and Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade receivables	3,433	3,346
Other	362	313
Allowances for uncollectible accounts	(129)	(128)
Receivables	$ 3,666	$ 3,531

Other receivables - Narrative (

Other receivables - Narrative (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Utilities and Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled revenue	$ 554	$ 665

Inventories (Detail)

Inventories (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 4,182	$ 3,479
Work in process and other	2,625	2,568
Finished manufactured goods	4,541	4,505
Goods acquired for resale	7,721	6,814
Total inventory	$ 19,069	$ 17,366

Property, plant and equipment_2

Property, plant and equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Insurance and Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 39,827	$ 37,641
Property, plant and equipment, accumulated depreciation	(19,199)	(17,773)
Total property, plant and equipment, net	20,628	19,868
Insurance and Other [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,536	2,523
Insurance and Other [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	9,959	9,409
Insurance and Other [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	22,574	21,190
Insurance and Other [Member] | Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,758	4,519
Railroad [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	73,189	70,940
Property, plant and equipment, accumulated depreciation	(10,004)	(8,627)
Total property, plant and equipment, net	63,185	62,313
Railroad [Member] | Land, track structure and other roadway [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	59,509	57,408
Railroad [Member] | Locomotives, freight cars and other equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	13,016	12,543
Railroad [Member] | Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	664	989
Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	96,246	91,891
Property, plant and equipment, accumulated depreciation	(27,651)	(26,020)
Total property, plant and equipment, net	68,595	65,871
Utilities and Energy [Member] | Utility generation, transmission and distribution systems [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	77,288	74,660
Utilities and Energy [Member] | Interstate natural gas pipeline assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,524	7,176
Utilities and Energy [Member] | Independent power plants and other assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,324	7,499
Utilities and Energy [Member] | Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,110	2,556
Railroad, Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, net	$ 131,780	$ 128,184

Property, plant and equipment -

Property, plant and equipment - Depreciation expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 7,284	$ 6,968	$ 6,656
Insurance and Other [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	2,186	2,116	2,017
Railroad, Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 5,098	$ 4,852	$ 4,639

Equipment held for lease - Narr

Equipment held for lease - Narrative (Detail) - Insurance and Other [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, net	$ 14,298	$ 10,167
Equipment held for lease, gross	20,617	13,775
Equipment held for lease, accumulated depreciation	6,319	3,608
Aircraft repurchase liabilities and unearned lease revenues	4,593
Depreciation expense for equipment held for lease	1,102	$ 751	$ 755
Future minimum lease rentals to be received, 2019	2,493
Future minimum lease rentals to be received, 2020	1,771
Future minimum lease rentals to be received, 2021	1,222
Future minimum lease rentals to be received, 2022	779
Future minimum lease rentals to be received, 2023	421
Future minimum lease rentals to be received, thereafter	$ 377
Aircraft Sold Under Fractional Aircraft Ownership Programs [Member] | ASC 606 [Member]
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, net				$ 3,500
Equipment held for lease, gross				5,300
Equipment held for lease, accumulated depreciation				1,800
Aircraft repurchase liabilities and unearned lease revenues				$ 3,500

Equipment held for lease (Detai

Equipment held for lease (Detail) - Insurance and Other [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, gross	$ 20,617	$ 13,775
Equipment held for lease, accumulated depreciation	(6,319)	(3,608)
Equipment held for lease, net	14,298	10,167
Railcars [Member]
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, gross	8,862	8,352
Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, gross	7,376	1,456
Other Equipment Held for Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Equipment held for lease, gross	$ 4,379	$ 3,967

Goodwill and other intangible_3

Goodwill and other intangible assets - Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Balance at beginning of year	$ 81,258	$ 79,486
Acquisitions of businesses	376	1,545
Other, including foreign currency translation	(609)	227
Balance at end of year	$ 81,025	$ 81,258

Goodwill and other intangible_4

Goodwill and other intangible assets - Intangible assets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 41,504	$ 41,213
Accumulated amortization	9,356	8,031
Insurance and Other [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	40,493	40,225
Accumulated amortization	8,994	7,707
Railroad, Utilities and Energy [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,011	988
Accumulated amortization	362	324
Trademarks and trade names [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	5,368	5,381
Accumulated amortization	750	692
Customer relationships [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,375	28,322
Accumulated amortization	4,573	3,722
Other intangible assets [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,315	3,169
Accumulated amortization	1,243	1,124
Patents and technology [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	4,446	4,341
Accumulated amortization	$ 2,790	$ 2,493

Goodwill and other intangible_5

Goodwill and other intangible assets - Intangible assets - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization expense	$ 1,393	$ 1,469	$ 1,490
Estimated amortization expense - 2019	1,318
Estimated amortization expense - 2020	1,224
Estimated amortization expense - 2021	1,136
Estimated amortization expense - 2022	1,063
Estimated amortization expense - 2023	1,018
Intangible assets with indefinite lives, excluding goodwill	$ 18,900	$ 18,900

Derivative contracts (Detail)

Derivative contracts (Detail) - Not Designated as Hedging Instrument [Member] - Equity Index Put Options [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Liabilities	$ 2,452	$ 2,172
Notional Value	$ 26,759	$ 28,753

Derivative contracts - Narrativ

Derivative contracts - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative contract gains (losses)	$ (300,000,000)	$ 718,000,000	$ 751,000,000
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative contract gains (losses)			751,000,000
Collateral posting requirements under contracts with collateral provisions	0
Additional collateral posting requirements	1,100,000,000
Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member]
Derivative [Line Items]
Derivative contract gains (losses)	$ (300,000,000)	718,000,000	662,000,000
Weighted average remaining life of derivative contracts	1 year 10 months 24 days
Notional value of contracts expired and terminated	$ 1,200,000,000
Notional value of contracts that will expire in next fiscal year	12,200,000,000
Premiums received at contract inception dates	4,000,000,000
Aggregate intrinsic value of equity index put option contracts	1,653,000,000	789,000,000
Liabilities	$ 2,452,000,000	2,172,000,000
Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member] | Maximum [Member]
Derivative [Line Items]
Derivative inception month and year	2008-03
Derivative maturity month and year	2025-10
Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Derivative maturity month and year	2019-04
Not Designated as Hedging Instrument [Member] | Credit Default [Member]
Derivative [Line Items]
Derivative contract gains (losses)			$ 89,000,000
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | Utilities and Energy [Member]
Derivative [Line Items]
Assets	$ 172,000,000	142,000,000
Accounts Payable, Accruals and Other Liabilities [Member] | Not Designated as Hedging Instrument [Member] | Utilities and Energy [Member]
Derivative [Line Items]
Liabilities	$ 111,000,000	$ 82,000,000

Supplemental cash flow inform_3

Supplemental cash flow information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for income taxes	$ 4,354	$ 3,286	$ 4,719
Liabilities assumed in connection with business acquisitions	3,735	747	16,555
Equity securities exchanged in connection with business acquisitions			4,239
Conversions and other exchanges of investments			4,154
Equity securities surrendered in connection with warrant exercise		4,965
Insurance and Other [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for interest	1,111	1,260	944
Railroad, Utilities and Energy [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for interest	$ 2,867	$ 2,828	$ 2,788

Unpaid losses and loss adjust_3

Unpaid losses and loss adjustment expenses - Reconciliation of changes in claim liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Gross liabilities at beginning of year	$ 61,122	$ 53,379	$ 50,519
Reinsurance recoverable on unpaid losses at beginning of year	(3,201)	(3,338)	(3,307)
Net liabilities at beginning of year	57,921	50,041	47,212
Net liabilities at end of year	65,398	57,921	50,041
Reinsurance recoverable on unpaid losses at end of year	3,060	3,201	3,338
Gross liabilities at end of year	68,458	61,122	53,379
Property and Casualty Insurance and Reinsurance, Excluding Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses, current accident year events	39,876	37,702	30,636
Incurred losses and loss adjustment expenses, prior accident years' events	(1,406)	(544)	(1,443)
Total incurred losses and loss adjustment expenses	38,470	37,158	29,193
Paid losses and loss adjustment expenses, current accident year events	(18,391)	(17,425)	(14,898)
Paid losses and loss adjustment expenses, prior accident years' events	(15,452)	(12,507)	(10,929)
Total payments	(33,843)	(29,932)	(25,827)
Foreign currency translation adjustment	(331)	$ 654	$ (537)
Business acquisition	$ 3,181

Unpaid losses and loss adjust_4

Unpaid losses and loss adjustment expenses - Narrative (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)Event	Dec. 31, 2017USD ($)Event	Dec. 31, 2016USD ($)
Property and Casualty Insurance and Reinsurance, Excluding Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses with respect to current accident year events	$ 39,876	$ 37,702	$ 30,636
Number of significant catastrophe events | Event	4	6
Incurred losses and loss adjustment expenses for (reductions of) prior years' accident events	$ (1,406)	$ (544)	$ (1,443)
Percentage of reduction of net liabilities	2.40%	1.10%	3.10%
Liabilities for environmental, asbestos and latent injury claims, net of reinsurance	$ 1,700	$ 1,600
Property and Casualty Insurance and Reinsurance, Excluding Retroactive Reinsurance [Member] | Significant Catastrophe Events [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses with respect to current accident year events	1,600	3,000
Primary Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses for (reductions of) prior years' accident events	(937)	(249)	$ (569)
Property and Casualty Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses for (reductions of) prior years' accident events	$ (469)	$ (295)	$ (874)

Unpaid losses and loss adjust_5

Unpaid losses and loss adjustment expenses - Reconciliation of unpaid losses and allocated loss adjustment expenses to balance sheet liability (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reinsurance recoverable	$ 3,060	$ 3,201	$ 3,338	$ 3,307
Unpaid losses and loss adjustment expenses	68,458	$ 61,122	$ 53,379	$ 50,519
Insurance Group [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	62,661
Reinsurance recoverable	3,051
Unpaid unallocated loss adjustment expenses	2,015
Other unpaid losses and loss adjustment expenses	731
Unpaid losses and loss adjustment expenses	68,458
Insurance Group [Member] | GEICO [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	17,318
Reinsurance recoverable	896
Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member] | Property [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	9,395
Reinsurance recoverable	312
Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	19,966
Reinsurance recoverable	850
Insurance Group [Member] | Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	7,288
Reinsurance recoverable	53
Insurance Group [Member] | Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unpaid losses and ALAE, net	8,694
Reinsurance recoverable	$ 940

Unpaid losses and loss adjust_6

Unpaid losses and loss adjustment expenses - Incurred and paid losses and allocated loss adjustment expenses (Detail) - Insurance Group [Member] Claim in Thousands, $ in Millions	Dec. 31, 2018USD ($)Claim	Dec. 31, 2017USD ($)	[1]	Dec. 31, 2016USD ($)	[1]	Dec. 31, 2015USD ($)	[1]	Dec. 31, 2014USD ($)	[1]	Dec. 31, 2013USD ($)	[1]	Dec. 31, 2012USD ($)	[1]	Dec. 31, 2011USD ($)	[1]	Dec. 31, 2010USD ($)	[1]	Dec. 31, 2009USD ($)	[1]
Claims Development [Line Items]
Net unpaid losses and ALAE	$ 62,661
GEICO [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	97,431
Cumulative Paid Losses and ALAE	80,699
Net unpaid losses and ALAE	17,318
GEICO [Member] | 2014 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	14,651	$ 14,589		$ 14,559		$ 14,572		$ 14,680
IBNR and Case Development Liabilities	$ 148
Cumulative Number of Reported Claims | Claim	7,976
Cumulative Paid Losses and ALAE	$ 14,273	13,850		13,140		12,036		9,199
GEICO [Member] | 2015 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	17,039	16,993		16,875		16,887
IBNR and Case Development Liabilities	$ 319
Cumulative Number of Reported Claims | Claim	8,926
Cumulative Paid Losses and ALAE	$ 16,186	15,285		13,858		10,606
GEICO [Member] | 2016 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	19,364	19,390		19,106
IBNR and Case Development Liabilities	$ 823
Cumulative Number of Reported Claims | Claim	9,633
Cumulative Paid Losses and ALAE	$ 17,493	15,862		12,020
GEICO [Member] | 2017 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	22,257	22,675
IBNR and Case Development Liabilities	$ 2,208
Cumulative Number of Reported Claims | Claim	10,816
Cumulative Paid Losses and ALAE	$ 18,249	13,878
GEICO [Member] | 2018 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	24,120
IBNR and Case Development Liabilities	$ 4,659
Cumulative Number of Reported Claims | Claim	10,968
Cumulative Paid Losses and ALAE	$ 14,498
GEICO [Member] | 2014-2018 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE	16,732
GEICO [Member] | Before 2014 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE for accident years before earliest accident year presented	586
Berkshire Hathaway Reinsurance Group [Member] | Property [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	30,598
Cumulative Paid Losses and ALAE	21,618
Net unpaid losses and ALAE	9,395
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2014 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,115	2,171		2,315		2,427		2,621
IBNR and Case Development Liabilities	120
Cumulative Paid Losses and ALAE	1,773	1,708		1,569		1,244		465
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2015 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,938	2,531		3,088		3,244
IBNR and Case Development Liabilities	136
Cumulative Paid Losses and ALAE	2,135	1,940		1,590		569
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2016 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	3,625	3,906		3,267
IBNR and Case Development Liabilities	583
Cumulative Paid Losses and ALAE	2,187	1,792		703
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2017 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	4,958	5,248
IBNR and Case Development Liabilities	600
Cumulative Paid Losses and ALAE	2,713	1,026
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2018 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	4,373
IBNR and Case Development Liabilities	2,125
Cumulative Paid Losses and ALAE	910
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2009 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,984	1,984		1,985		1,990		2,031		$ 2,058		$ 2,154		$ 2,232		$ 2,037		$ 2,366
IBNR and Case Development Liabilities	7
Cumulative Paid Losses and ALAE	1,963	1,961		1,959		1,950		1,916		1,846		1,777		1,613		1,110		402
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2010 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,114	2,106		2,126		2,145		2,180		2,274		2,408		2,380		2,523
IBNR and Case Development Liabilities	23
Cumulative Paid Losses and ALAE	2,065	2,058		2,033		1,987		1,931		1,772		1,506		1,024		336
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2011 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	3,652	3,666		3,689		3,719		3,720		3,810		4,084		4,300
IBNR and Case Development Liabilities	52
Cumulative Paid Losses and ALAE	3,485	3,440		3,398		3,310		3,200		2,931		2,282		701
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2012 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,315	2,333		2,336		2,389		2,629		2,833		3,144
IBNR and Case Development Liabilities	65
Cumulative Paid Losses and ALAE	2,123	2,103		2,028		1,939		1,801		1,222		266
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2013 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,524	2,584		2,604		2,695		3,039		3,196
IBNR and Case Development Liabilities	105
Cumulative Paid Losses and ALAE	2,264	2,184		2,063		1,866		1,427		516
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | 2009-2018 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE	8,980
Berkshire Hathaway Reinsurance Group [Member] | Property [Member] | Before 2009 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE for accident years before earliest accident year presented	415
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	22,609
Cumulative Paid Losses and ALAE	11,113
Net unpaid losses and ALAE	19,966
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2014 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,905	1,991		2,029		2,061		1,867
IBNR and Case Development Liabilities	611
Cumulative Paid Losses and ALAE	875	753		644		478		150
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2015 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,000	2,099		2,072		1,875
IBNR and Case Development Liabilities	647
Cumulative Paid Losses and ALAE	834	714		491		196
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2016 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,014	2,107		1,903
IBNR and Case Development Liabilities	818
Cumulative Paid Losses and ALAE	734	556		253
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2017 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,676	2,189
IBNR and Case Development Liabilities	1,141
Cumulative Paid Losses and ALAE	568	231
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2018 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,917
IBNR and Case Development Liabilities	1,856
Cumulative Paid Losses and ALAE	267
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2009 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,209	2,192		2,231		2,292		2,339		2,414		2,476		2,546		2,687		2,375
IBNR and Case Development Liabilities	213
Cumulative Paid Losses and ALAE	1,716	1,684		1,658		1,622		1,586		1,430		1,211		940		852		247
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2010 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,963	1,883		2,044		2,090		2,139		2,258		2,322		2,387		2,301
IBNR and Case Development Liabilities	228
Cumulative Paid Losses and ALAE	1,531	1,482		1,437		1,374		1,278		1,026		838		546		118
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2011 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,282	2,320		2,327		2,418		2,508		2,567		2,696		2,609
IBNR and Case Development Liabilities	363
Cumulative Paid Losses and ALAE	1,698	1,659		1,581		1,489		1,400		1,160		817		292
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2012 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,615	2,682		2,793		2,864		2,799		2,964		2,789
IBNR and Case Development Liabilities	514
Cumulative Paid Losses and ALAE	1,750	1,651		1,527		1,370		1,140		749		309
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2013 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,028	2,082		2,134		2,290		2,259		2,130
IBNR and Case Development Liabilities	544
Cumulative Paid Losses and ALAE	1,140	1,039		935		807		521		291
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | 2009-2018 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE	11,496
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member] | Before 2009 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE for accident years before earliest accident year presented	8,470
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	12,058
Cumulative Paid Losses and ALAE	5,149
Net unpaid losses and ALAE	7,288
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2014 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,218	1,246		1,305		1,375		1,370
IBNR and Case Development Liabilities	$ 296
Cumulative Number of Reported Claims | Claim	13
Cumulative Paid Losses and ALAE	$ 540	396		238		106		21
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2015 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,290	1,269		1,342		1,374
IBNR and Case Development Liabilities	$ 450
Cumulative Number of Reported Claims | Claim	14
Cumulative Paid Losses and ALAE	$ 382	218		108		23
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2016 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,414	1,416		1,392
IBNR and Case Development Liabilities	$ 641
Cumulative Number of Reported Claims | Claim	14
Cumulative Paid Losses and ALAE	$ 274	115		22
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2017 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,499	1,466
IBNR and Case Development Liabilities	$ 1,011
Cumulative Number of Reported Claims | Claim	18
Cumulative Paid Losses and ALAE	$ 128	27
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2018 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,602
IBNR and Case Development Liabilities	$ 1,410
Cumulative Number of Reported Claims | Claim	15
Cumulative Paid Losses and ALAE	$ 35
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2009 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	904	922		941		988		1,060		1,153		1,251		1,294		1,349		1,423
IBNR and Case Development Liabilities	$ 22
Cumulative Number of Reported Claims | Claim	13
Cumulative Paid Losses and ALAE	$ 810	789		753		699		619		480		350		203		90		5
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2010 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,006	1,031		1,085		1,140		1,234		1,329		1,348		1,346		1,399
IBNR and Case Development Liabilities	$ 43
Cumulative Number of Reported Claims | Claim	13
Cumulative Paid Losses and ALAE	$ 853	810		745		654		526		377		224		95		15
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2011 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,004	1,050		1,115		1,173		1,262		1,321		1,334		1,346
IBNR and Case Development Liabilities	$ 71
Cumulative Number of Reported Claims | Claim	13
Cumulative Paid Losses and ALAE	$ 767	711		632		517		356		200		82		16
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2012 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,035	1,078		1,168		1,223		1,277		1,306		1,336
IBNR and Case Development Liabilities	$ 108
Cumulative Number of Reported Claims | Claim	13
Cumulative Paid Losses and ALAE	$ 725	642		522		377		218		93		15
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2013 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,086	1,127		1,195		1,261		1,296		1,328
IBNR and Case Development Liabilities	$ 160
Cumulative Number of Reported Claims | Claim	12
Cumulative Paid Losses and ALAE	$ 635	518		368		219		90		15
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | 2009-2018 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE	6,909
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member] | Before 2009 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE for accident years before earliest accident year presented	379
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	16,718
Cumulative Paid Losses and ALAE	8,346
Net unpaid losses and ALAE	8,694
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2014 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,572	1,641		1,716		1,737		1,866
IBNR and Case Development Liabilities	$ 287
Cumulative Number of Reported Claims | Claim	112
Cumulative Paid Losses and ALAE	$ 1,155	1,046		837		581		247
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2015 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,124	2,156		2,244		2,314
IBNR and Case Development Liabilities	$ 445
Cumulative Number of Reported Claims | Claim	133
Cumulative Paid Losses and ALAE	$ 1,328	1,044		715		297
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2016 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	2,475	2,561		2,656
IBNR and Case Development Liabilities	$ 833
Cumulative Number of Reported Claims | Claim	127
Cumulative Paid Losses and ALAE	$ 1,181	792		332
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2017 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	3,122	3,262
IBNR and Case Development Liabilities	$ 1,395
Cumulative Number of Reported Claims | Claim	143
Cumulative Paid Losses and ALAE	$ 1,078	467
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2018 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	3,761
IBNR and Case Development Liabilities	$ 2,459
Cumulative Number of Reported Claims | Claim	142
Cumulative Paid Losses and ALAE	$ 570
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2009 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	562	576		585		589		595		609		632		676		673		732
IBNR and Case Development Liabilities	$ 40
Cumulative Number of Reported Claims | Claim	46
Cumulative Paid Losses and ALAE	$ 507	503		499		488		464		434		389		328		228		$ 99
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2010 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	553	562		576		584		589		609		644		675		715
IBNR and Case Development Liabilities	$ 42
Cumulative Number of Reported Claims | Claim	47
Cumulative Paid Losses and ALAE	$ 491	484		479		465		437		393		327		250		$ 106
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2011 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	622	632		647		653		657		709		706		786
IBNR and Case Development Liabilities	$ 72
Cumulative Number of Reported Claims | Claim	51
Cumulative Paid Losses and ALAE	$ 522	512		498		470		415		344		222		$ 114
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2012 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	779	792		815		828		876		887		907
IBNR and Case Development Liabilities	$ 105
Cumulative Number of Reported Claims | Claim	63
Cumulative Paid Losses and ALAE	$ 627	607		576		515		422		301		$ 101
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2013 [Member]
Claims Development [Line Items]
Incurred Losses and ALAE	1,148	1,173		1,210		1,257		1,310		1,339
IBNR and Case Development Liabilities	$ 188
Cumulative Number of Reported Claims | Claim	83
Cumulative Paid Losses and ALAE	$ 887	$ 842		$ 776		$ 650		$ 452		$ 193
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | 2009-2018 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE	8,372
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member] | Before 2009 [Member]
Claims Development [Line Items]
Net unpaid losses and ALAE for accident years before earliest accident year presented	$ 322
[1]	Unaudited supplemental information

Unpaid losses and loss adjust_7

Unpaid losses and loss adjustment expenses - Average historical claims duration (Detail) - Insurance Group [Member]	Dec. 31, 2018
GEICO [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout of incurred losses, net of reinsurance, year one	61.70%
Average annual percentage payout of incurred losses, net of reinsurance, year two	19.60%
Average annual percentage payout of incurred losses, net of reinsurance, year three	8.10%
Average annual percentage payout of incurred losses, net of reinsurance, year four	4.90%
Average annual percentage payout of incurred losses, net of reinsurance, year five	2.80%
Berkshire Hathaway Reinsurance Group [Member] | Property [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout of incurred losses, net of reinsurance, year one	19.00%
Average annual percentage payout of incurred losses, net of reinsurance, year two	36.10%
Average annual percentage payout of incurred losses, net of reinsurance, year three	18.30%
Average annual percentage payout of incurred losses, net of reinsurance, year four	7.90%
Average annual percentage payout of incurred losses, net of reinsurance, year five	4.30%
Average annual percentage payout of incurred losses, net of reinsurance, year six	3.00%
Average annual percentage payout of incurred losses, net of reinsurance, year seven	1.50%
Average annual percentage payout of incurred losses, net of reinsurance, year eight	1.00%
Average annual percentage payout of incurred losses, net of reinsurance, year nine	0.20%
Average annual percentage payout of incurred losses, net of reinsurance, year ten	0.10%
Berkshire Hathaway Reinsurance Group [Member] | Casualty [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout of incurred losses, net of reinsurance, year one	10.40%
Average annual percentage payout of incurred losses, net of reinsurance, year two	17.80%
Average annual percentage payout of incurred losses, net of reinsurance, year three	11.50%
Average annual percentage payout of incurred losses, net of reinsurance, year four	8.50%
Average annual percentage payout of incurred losses, net of reinsurance, year five	7.40%
Average annual percentage payout of incurred losses, net of reinsurance, year six	5.10%
Average annual percentage payout of incurred losses, net of reinsurance, year seven	3.00%
Average annual percentage payout of incurred losses, net of reinsurance, year eight	1.90%
Average annual percentage payout of incurred losses, net of reinsurance, year nine	1.80%
Average annual percentage payout of incurred losses, net of reinsurance, year ten	1.40%
Berkshire Hathaway Primary Group [Member] | Medical Professional Liability [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout of incurred losses, net of reinsurance, year one	1.60%
Average annual percentage payout of incurred losses, net of reinsurance, year two	7.30%
Average annual percentage payout of incurred losses, net of reinsurance, year three	11.50%
Average annual percentage payout of incurred losses, net of reinsurance, year four	14.50%
Average annual percentage payout of incurred losses, net of reinsurance, year five	14.10%
Average annual percentage payout of incurred losses, net of reinsurance, year six	12.40%
Average annual percentage payout of incurred losses, net of reinsurance, year seven	8.40%
Average annual percentage payout of incurred losses, net of reinsurance, year eight	6.00%
Average annual percentage payout of incurred losses, net of reinsurance, year nine	4.10%
Average annual percentage payout of incurred losses, net of reinsurance, year ten	2.30%
Berkshire Hathaway Primary Group [Member] | Workers' Compensation and Other Casualty [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout of incurred losses, net of reinsurance, year one	15.80%
Average annual percentage payout of incurred losses, net of reinsurance, year two	21.50%
Average annual percentage payout of incurred losses, net of reinsurance, year three	16.50%
Average annual percentage payout of incurred losses, net of reinsurance, year four	12.00%
Average annual percentage payout of incurred losses, net of reinsurance, year five	7.60%
Average annual percentage payout of incurred losses, net of reinsurance, year six	4.60%
Average annual percentage payout of incurred losses, net of reinsurance, year seven	2.90%
Average annual percentage payout of incurred losses, net of reinsurance, year eight	1.50%
Average annual percentage payout of incurred losses, net of reinsurance, year nine	1.00%
Average annual percentage payout of incurred losses, net of reinsurance, year ten	0.70%

Retroactive reinsurance contr_3

Retroactive reinsurance contracts - Reconciliation of changes in claim liabilities and deferred charge assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Unpaid losses and loss adjustment expenses, beginning of year	$ 42,937	$ 24,972	$ 24,058
Unpaid losses and loss adjustment expenses, end of year	41,834	42,937	24,972
Deferred charges reinsurance assumed, beginning of year	(15,278)	(8,047)	(7,687)
Deferred charges reinsurance assumed, end of year	(14,104)	(15,278)	(8,047)
Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses, prior years' contracts	919	458	451
Total incurred losses and loss adjustment expenses	1,436	11,733	1,713
Unpaid Losses and Loss Adjustment Expenses [Member] | Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses, current year contracts	603	19,005	2,136
Incurred losses and loss adjustment expenses, prior years' contracts	(341)	(41)	(63)
Total incurred losses and loss adjustment expenses	262	18,964	2,073
Paid losses and loss adjustment expenses	(1,365)	(999)	(1,159)
Deferred Charges Reinsurance Assumed [Member] | Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses, current year contracts	(86)	(7,730)	(874)
Incurred losses and loss adjustment expenses, prior years' contracts	1,260	499	514
Total incurred losses and loss adjustment expenses	$ 1,174	$ (7,231)	$ (360)

Retroactive reinsurance contr_4

Retroactive reinsurance contracts - Narrative (Detail) - USD ($)	Feb. 02, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effects of Reinsurance [Line Items]
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts		$ 42,937,000,000	$ 41,834,000,000	$ 42,937,000,000	$ 24,972,000,000	$ 24,058,000,000
Deferred charges under retroactive reinsurance contracts		15,278,000,000	14,104,000,000	15,278,000,000	8,047,000,000	$ 7,687,000,000
Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses			1,436,000,000	11,733,000,000	1,713,000,000
Incurred losses and loss adjustment expenses, prior years' contracts			919,000,000	458,000,000	451,000,000
Liabilities for environmental, asbestos and latent injury claims		14,000,000,000	13,100,000,000	14,000,000,000
Unpaid Losses and Loss Adjustment Expenses [Member] | Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses			262,000,000	18,964,000,000	2,073,000,000
Incurred losses and loss adjustment expenses, prior years' contracts			(341,000,000)	(41,000,000)	(63,000,000)
Deferred Charges Reinsurance Assumed [Member] | Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses			1,174,000,000	(7,231,000,000)	(360,000,000)
Incurred losses and loss adjustment expenses, prior years' contracts			1,260,000,000	499,000,000	$ 514,000,000
NICO [Member] | AIG [Member] | Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Percentage of losses and allocated loss adjustment expenses reinsured in excess of retained amount	80.00%
Losses and allocated loss adjustment expenses retained amount	$ 25,000,000,000
Premiums earned	10,200,000,000
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts	16,400,000,000	18,200,000,000	18,200,000,000	18,200,000,000
Deferred charges under retroactive reinsurance contracts	6,200,000,000	7,500,000,000	$ 6,900,000,000	$ 7,500,000,000
NICO [Member] | AIG [Member] | Retroactive Reinsurance [Member] | Maximum [Member]
Effects of Reinsurance [Line Items]
Losses and allocated loss adjustment expenses reinsured in excess of retained amount	$ 25,000,000,000
NICO [Member] | Unpaid Losses and Loss Adjustment Expenses [Member] | AIG [Member] | Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses		1,800,000,000
NICO [Member] | Deferred Charges Reinsurance Assumed [Member] | AIG [Member] | Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses		$ (1,700,000,000)

Notes payable and other borro_3

Notes payable and other borrowings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Principal payments on debt - 2019	$ 12,212
Principal payments on debt - 2020	5,589
Principal payments on debt - 2021	5,521
Principal payments on debt - 2022	4,962
Principal payments on debt - 2023	9,437
Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	16,871	$ 18,767
Principal payments on debt - 2019	752
Principal payments on debt - 2020	1,149
Principal payments on debt - 2021	2,131
Principal payments on debt - 2022	613
Principal payments on debt - 2023	3,991
Insurance and Other [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	34,975	40,409
Principal payments on debt - 2019	6,760
Principal payments on debt - 2020	2,811
Principal payments on debt - 2021	3,261
Principal payments on debt - 2022	1,616
Principal payments on debt - 2023	5,371
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 9,065	10,603
Weighted average interest rate, percentage	3.10%
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Euro Denominated [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 7,806	8,164
Weighted average interest rate, percentage	1.10%
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Minimum [Member] | U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Minimum [Member] | Euro Denominated [Member]
Debt Instrument [Line Items]
Debt maturity year	2,020
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Maximum [Member] | U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Debt maturity year	2,047
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Maximum [Member] | Euro Denominated [Member]
Debt Instrument [Line Items]
Debt maturity year	2,035
Insurance and Other [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Other borrowings	$ 5,597	6,884
Short-term debt	$ 1,857	1,832
Weighted average interest rate, percentage	4.00%
Short-term debt, weighted average interest rate	4.30%
Insurance and Other [Member] | Subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Insurance and Other [Member] | Subsidiaries [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,045
Insurance and Other [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 10,650	12,926
Weighted average interest rate, percentage	3.40%
Insurance and Other [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Insurance and Other [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,048
Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 62,515	62,178
Principal payments on debt - 2019	5,452
Principal payments on debt - 2020	2,778
Principal payments on debt - 2021	2,260
Principal payments on debt - 2022	3,346
Principal payments on debt - 2023	$ 4,066
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	4.60%
Senior unsecured debt	$ 8,577	6,452
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,020
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,049
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Subsidiaries [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 28,196	28,739
Weighted average interest rate, percentage	4.70%
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Subsidiaries [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,064
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Short-term debt	$ 2,516	4,488
Short-term debt, weighted average interest rate	3.10%
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Burlington Northern Santa Fe and subsidiaries [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 23,226	$ 22,499
Weighted average interest rate, percentage	4.70%
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Burlington Northern Santa Fe and subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Burlington Northern Santa Fe and subsidiaries [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,097

Notes payable and other borro_4

Notes payable and other borrowings - Narrative (Detail) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2019	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Gain (loss) attributable to changes in foreign currency exchange rates			$ 366	$ (1,008)	$ 244
Repayments of borrowings			$ 1,563	1,145	1,125
Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage			4.00%
Euro Denominated [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage			1.10%
Euro Denominated [Member] | Senior Notes [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Gain (loss) attributable to changes in foreign currency exchange rates			$ 366	$ (990)	$ 264
Subsidiaries Excluding Berkshire Hathaway Finance Corporation [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Guarantee obligation			1,700
Berkshire Hathaway Energy and Subsidiaries [Member] | Debt Due 2020 To 2049 [Member] | Subsidiaries [Member] | Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Principal amount of debt issued			$ 5,500
Weighted average interest rate, percentage			3.60%
BNSF [Member] | Debentures Due 2048 [Member] | Senior Unsecured Debentures [Member] | Subsidiaries [Member] | Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Principal amount of debt issued			$ 1,500
Weighted average interest rate, percentage			4.10%
Berkshire Hathaway Finance Corporation [Member] | Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage			3.40%
Berkshire Hathaway Finance Corporation [Member] | Senior Notes [Member] | Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Repayments of borrowings			$ 4,600
Berkshire Hathaway Finance Corporation [Member] | Notes Due 2048 at 4.2% [Member] | Senior Notes [Member] | Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 2,350
Debt instrument, interest rate, stated percentage		4.20%
Berkshire Hathaway Finance Corporation [Member] | Subsequent Event [Member] | Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Repayments of borrowings	$ 950
Berkshire Hathaway Finance Corporation [Member] | Subsequent Event [Member] | Notes Due 2048 at 4.25% [Member] | Senior Notes [Member] | Subsidiaries [Member] | Insurance and Other [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 1,250
Debt instrument, interest rate, stated percentage	4.25%

Notes payable and other borro_5

Notes payable and other borrowings - Credit agreements - Narrative (Detail) - Line of Credit and Commercial Paper Facilities [Member] - Subsidiaries [Member] $ in Billions	Dec. 31, 2018USD ($)
Line of Credit Facility [Line Items]
Unused lines of credit available	$ 7.3
Berkshire Hathaway Energy and Subsidiaries [Member]
Line of Credit Facility [Line Items]
Unused lines of credit available	$ 6.1

Income taxes - Liabilities (Det

Income taxes - Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Currently payable (receivable)	$ 323	$ (129)
Deferred	50,503	56,182
Other income tax liabilities	549	554
Income taxes, principally deferred	$ 51,375	$ 56,607

Income taxes - Narrative (Detai

Income taxes - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory U.S. Corporate income tax rate		21.00%	35.00%
Reduction in deferred income tax liabilities related to change in U.S. statutory income tax rate			$ 35,600
Income tax benefit related to change in U.S. statutory income tax rate			29,600
Increase in regulatory liabilities for deferred income tax liability reduction related to change in U.S. statutory income tax rate			6,000
Income tax charge with respect to deemed repatriation of accumulated undistributed earnings of foreign subsidiaries			1,400
Net income tax benefit as a result of enactment of the TCJA	$ 28,200		28,200
Reduction of estimate of income taxes on deemed repatriation of earnings of foreign subsidiaries		$ 141
Unrecognized tax benefits	$ 554	549	$ 554
Unrecognized tax benefits that would impact effective tax rate		$ 452

Income taxes - Deferred taxes (

Income taxes - Deferred taxes (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Investments - unrealized appreciation and cost basis differences	$ 17,765	$ 24,251
Deferred charges reinsurance assumed	2,970	3,226
Property, plant and equipment	28,279	26,671
Goodwill and other intangible assets	7,199	7,204
Other deferred tax liabilities	3,187	3,216
Deferred tax liabilities	59,400	64,568
Deferred tax assets:
Unpaid losses and loss adjustment expenses	(1,238)	(1,231)
Unearned premiums	(767)	(345)
Accrued liabilities	(1,956)	(2,501)
Regulatory liabilities	(1,673)	(1,707)
Other deferred tax assets	(3,263)	(2,602)
Deferred tax assets	(8,897)	(8,386)
Net deferred tax liability	$ 50,503	$ 56,182

Income taxes - Income tax expen

Income taxes - Income tax expense components (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax expense:
Federal	$ (1,613)	$ (23,427)	$ 7,796
State	175	894	556
Foreign	1,117	1,018	888
Total income taxes	(321)	(21,515)	9,240
Income tax expense:
Current	5,176	3,299	6,565
Deferred	(5,497)	(24,814)	2,675
Total income taxes	$ (321)	$ (21,515)	$ 9,240

Income taxes - Income tax exp_2

Income taxes - Income tax expense reconciliation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax expense reconciliation
Earnings before income taxes	$ 4,001	$ 23,838	$ 33,667
Hypothetical income tax expense computed at the U.S. federal statutory rate	840	8,343	11,783
Dividends received deduction and tax exempt interest	(393)	(905)	(789)
State income taxes, less U.S. federal income tax benefit	138	465	361
Foreign tax rate differences	271	(339)	(421)
U.S. income tax credits	(711)	(636)	(518)
Non-taxable exchange of investments			(1,143)
Net benefit from the enactment of the TCJA	(302)	(28,200)
Other differences, net	(164)	(243)	(33)
Total income taxes	$ (321)	$ (21,515)	$ 9,240

Dividend restrictions - Insur_2

Dividend restrictions - Insurance subsidiaries (Detail) - USD ($) $ in Billions	Dec. 31, 2018	Dec. 31, 2017
Principal Insurance Subsidiaries [Member]
Statutory Accounting Practices [Line Items]
Amount available for payment of dividends without prior regulatory approval during 2019	$ 16
United States Based Property and Casualty Insurance Subsidiaries [Member]
Statutory Accounting Practices [Line Items]
Statutory shareholders' equity	$ 162	$ 170

Fair value measurements - Finan

Fair value measurements - Financial assets and liabilities (Detail) - USD ($) $ in Millions		Dec. 31, 2018		Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		$ 19,898		$ 21,353
Investments in equity securities		172,757	[1]	170,540	[2]
Loans and finance receivables - carrying value		16,280		13,748
Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - carrying value		62,515		62,178
Insurance and Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		19,898		21,353
Investments in equity securities		172,757		170,540
Equity method investments - carrying value		17,325		21,024
Loans and finance receivables - carrying value		16,280		13,748
Derivative contract liabilities		2,452		2,172
Notes payable and other borrowings - carrying value		34,975		40,409
The Kraft Heinz Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments - carrying value		13,813		17,635
Equity method investments - fair value		14,007		25,306
U.S. Treasury, U.S. government corporations and agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		4,223		3,953
States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		189		854
Foreign governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,502		8,822
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,440		6,862
Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		544		862
Fair Value, Measurements, Recurring [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities		172,253		170,494
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities		203		46
Loans and finance receivables - fair value		1,531		17
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities		301
Loans and finance receivables - fair value		14,846		14,119
Fair Value, Measurements, Recurring [Member] | Railroad, Utilities and Energy [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		66,422		70,538
Fair Value, Measurements, Recurring [Member] | Insurance and Other [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		35,335		41,757
Fair Value, Measurements, Recurring [Member] | Insurance and Other [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		26		5
Fair Value, Measurements, Recurring [Member] | Equity Index Put Options [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities		2,452		2,172
Fair Value, Measurements, Recurring [Member] | Other Assets [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract assets	[3]	2		1
Fair Value, Measurements, Recurring [Member] | Other Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract assets	[3]	52		28
Fair Value, Measurements, Recurring [Member] | Other Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract assets	[3]	118		113
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Railroad, Utilities and Energy [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[3]	1		3
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Railroad, Utilities and Energy [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[3]	101		69
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Railroad, Utilities and Energy [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[3]	9		10
Fair Value, Measurements, Recurring [Member] | The Kraft Heinz Company [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments - fair value		14,007		25,306
Fair Value, Measurements, Recurring [Member] | U.S. Treasury, U.S. government corporations and agencies [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		2,933		2,360
Fair Value, Measurements, Recurring [Member] | U.S. Treasury, U.S. government corporations and agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		1,290		1,593
Fair Value, Measurements, Recurring [Member] | States, municipalities and political subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		189		854
Fair Value, Measurements, Recurring [Member] | Foreign governments [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		5,417		6,946
Fair Value, Measurements, Recurring [Member] | Foreign governments [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		2,085		1,876
Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,434		6,856
Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		6		6
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		544		862
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities		172,757		170,540
Loans and finance receivables - carrying value		16,280		13,748
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - carrying value		62,515		62,178
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Insurance and Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - carrying value		34,975		40,409
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Equity Index Put Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities		2,452		2,172
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract assets	[3]	172		142
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[3]	111		82
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | The Kraft Heinz Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments - carrying value		13,813		17,635
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		4,223		3,953
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		189		854
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Foreign governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,502		8,822
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,440		6,862
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		544		862
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities		172,757		170,540
Loans and finance receivables - fair value		16,377		14,136
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		66,422		70,538
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Insurance and Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		35,361		41,762
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Equity Index Put Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities		2,452		2,172
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract assets	[3]	172		142
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[3]	111		82
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | The Kraft Heinz Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments - fair value		14,007		25,306
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		4,223		3,953
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		189		854
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Foreign governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,502		8,822
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,440		6,862
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		$ 544		$ 862
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.5 billion; Apple Inc. - $40.3 billion; Bank of America Corporation - $22.6 billion; The Coca-Cola Company - $18.9 billion and Wells Fargo & Company - $20.7 billion).
[2]	Approximately 65% of the aggregate fair value was concentrated in five companies (American Express Company - $15.1 billion; Apple Inc. - $28.2 billion; Bank of America Corporation - $20.7 billion; The Coca-Cola Company - $18.4 billion and Wells Fargo & Company - $29.3 billion).
[3]	Assets are included in other assets and liabilities are included in accounts payable, accruals and other liabilities.

Fair value measurements - Signi

Fair value measurements - Significant unobservable inputs (Detail) - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurements Significant Unobservable Inputs [Line Items]
Net derivative contract liabilities - Beginning Balance	$ (2,069)	$ (2,824)	$ (3,785)
Net derivative contract liabilities - Gains (losses) included in earnings	(118)	888	880
Net derivative contract liabilities - Gains (losses) included in other comprehensive income	2	(3)	(2)
Net derivative contract liabilities - Gains (losses) included in regulatory assets and liabilities	3	(1)	(11)
Net derivative contract liabilities - Acquisitions	3
Net derivative contract liabilities - Dispositions and settlements	(164)	(129)	(101)
Net derivative contract liabilities - Transfers into/out of Level 3			195
Net derivative contract liabilities - Ending Balance	(2,343)	(2,069)	(2,824)
Investments in Equity and Fixed Maturity Securities [Member]
Fair Value Measurements Significant Unobservable Inputs [Line Items]
Beginning Balance	6	17,321	21,503
Gains (losses) included in earnings			3,593
Gains (losses) included in other comprehensive income		1,157	872
Acquisitions	302		10
Dispositions and settlements	(1)	(59)	(8,656)
Transfers into/out of Level 3		(18,413)	(1)
Ending Balance	$ 307	$ 6	$ 17,321

Fair value measurements - Narra

Fair value measurements - Narrative (Detail)	1 Months Ended
	Dec. 31, 2017USD ($)
RBI [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment redeemed, face amount	$ 3,000,000,000

Fair value measurements - Other

Fair value measurements - Other information (Detail) - Significant Unobservable Inputs (Level 3) [Member] - Equity Index Put Options [Member] - Fair Value, Measurements, Recurring [Member] $ in Millions	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative contract liabilities, fair value	$ 2,452	$ 2,172
Option Pricing Model [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative contract liabilities, fair value	$ 2,452
Option Pricing Model [Member] | Volatility [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable inputs	0.18

Common stock - Narrative (Detai

Common stock - Narrative (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)Voteshares	Dec. 31, 2017shares	Dec. 31, 2016shares	Dec. 31, 2015shares
Class of Stock [Line Items]
Preferred Stock, shares authorized	1,000,000
Preferred Stock, shares issued	0
Class A [Member]
Class of Stock [Line Items]
Number of votes entitled per share, number | Vote	1
Shares outstanding	729,316	751,075	776,378	808,422
Class B [Member]
Class of Stock [Line Items]
Number of votes entitled per share, number | Vote	0.0001
Economic equivalent of Class B share to Class A share	0.0667%
Number of shares of Class B stock obtainable from converting one Class A share	1,500
Shares outstanding	1,367,420,074	1,340,656,987	1,301,914,165	1,252,456,836
Equivalent Class A [Member]
Class of Stock [Line Items]
Shares outstanding	1,640,929	1,644,846
Common Stock Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase, authorization description	For several years, Berkshire had a common stock repurchase program, which permitted Berkshire to repurchase its Class A and Class B shares at prices no higher than a 20% premium over the book value of the shares. On July 17, 2018, Berkshire’s Board of Directors authorized an amendment to the program, permitting Berkshire to repurchase shares any time that Warren Buffett, Berkshire’s Chairman of the Board and Chief Executive Officer, and Charlie Munger, Vice Chairman of the Board, believe that the repurchase price is below Berkshire’s intrinsic value, conservatively determined.
Minimum cash, cash equivalents and U.S. Treasury Bills threshold after repurchase of common stock shares, amount | $	$ 20,000,000,000

Common stock (Detail)

Common stock (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class A [Member]
Class of Stock [Line Items]
Shares issued	742,213	762,755	788,058	820,102
Treasury shares	(12,897)	(11,680)	(11,680)	(11,680)
Shares outstanding	729,316	751,075	776,378	808,422
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition	(20,542)	(25,303)	(32,044)
Treasury stock acquired	(1,217)
Class B [Member]
Class of Stock [Line Items]
Shares issued	1,373,558,983	1,342,066,749	1,303,323,927	1,253,866,598
Treasury shares	(6,138,909)	(1,409,762)	(1,409,762)	(1,409,762)
Shares outstanding	1,367,420,074	1,340,656,987	1,301,914,165	1,252,456,836
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition	31,492,234	38,742,822	49,457,329
Treasury stock acquired	(4,729,147)

Common stock (Parenthetical) (D

Common stock (Parenthetical) (Detail)	Dec. 31, 2018$ / sharesshares
Class A [Member]
Class of Stock [Line Items]
Common Stock, par value per share | $ / shares	$ 5
Common Stock, shares authorized | shares	1,650,000
Class B [Member]
Class of Stock [Line Items]
Common Stock, par value per share | $ / shares	$ 0.0033
Common Stock, shares authorized | shares	3,225,000,000

Accumulated other comprehensi_3

Accumulated other comprehensive income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 351,954	$ 285,428	$ 257,696
Ending Balance	352,500	351,954	285,428
Unrealized appreciation of investments, net [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	62,093	43,176	38,598
Reclassifications to retained earnings upon adoption of new accounting standards	(61,340)
Other comprehensive income, net before reclassifications	(183)	19,826	9,011
Reclassifications before income taxes	(253)	(1,399)	(6,820)
Applicable income taxes	53	490	2,387
Ending Balance	370	62,093	43,176
Foreign currency translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,114)	(5,268)	(3,856)
Reclassifications to retained earnings upon adoption of new accounting standards	(65)
Other comprehensive income, net before reclassifications	(1,424)	2,151	(1,412)
Reclassifications before income taxes		3
Ending Balance	(4,603)	(3,114)	(5,268)
Prior service and actuarial gains/losses of defined benefit pension plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(420)	(593)	(762)
Reclassifications to retained earnings upon adoption of new accounting standards	36
Other comprehensive income, net before reclassifications	(513)	65	94
Reclassifications before income taxes	116	155	104
Applicable income taxes	(35)	(47)	(29)
Ending Balance	(816)	(420)	(593)
Other AOCI transactions [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	12	(17)	2
Reclassifications to retained earnings upon adoption of new accounting standards	(6)
Other comprehensive income, net before reclassifications	25	16	(48)
Reclassifications before income taxes	5	19	51
Applicable income taxes	(2)	(6)	(22)
Ending Balance	34	12	(17)
Accumulated other comprehensive income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	58,571	37,298	33,982
Reclassifications to retained earnings upon adoption of new accounting standards	(61,375)
Other comprehensive income, net before reclassifications	(2,095)	22,058	7,645
Reclassifications before income taxes	(132)	(1,222)	(6,665)
Applicable income taxes	16	437	2,336
Ending Balance	$ (5,015)	$ 58,571	$ 37,298

Revenue from contracts with cus

Revenue from contracts with customers disaggregated by reportable segment and source of revenue (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 175,445
Other revenue									72,392
Total revenues	$ 63,714	$ 63,450	$ 62,200	$ 58,473	$ 58,800	$ 59,507	$ 57,256	$ 64,370	247,837	$ 239,933	$ 215,114
Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									25,911
Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,323
Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,790
Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									33,518
Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									16,309
Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									8,181
Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,158
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									33,304
Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,951
Manufacturing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									58,430
Other revenue									3,340
Total revenues									61,770
Manufacturing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									25,707
Manufacturing Businesses [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,323
Manufacturing Businesses [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,790
Manufacturing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,091
Manufacturing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,519
McLane Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									49,911
Other revenue									76
Total revenues									49,987
McLane Company [Member] | Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									33,518
McLane Company [Member] | Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									16,309
McLane Company [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									84
Service and Retailing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									24,552
Other revenue									4,297
Total revenues									28,849
Service and Retailing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									204
Service and Retailing Businesses [Member] | Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									8,181
Service and Retailing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									12,067
Service and Retailing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									4,100
BNSF [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									23,652
Other revenue									51
Total revenues									23,703
BNSF [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									23,652
Berkshire Hathaway Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									18,900
Other revenue									1,070
Total revenues									19,970
Berkshire Hathaway Energy [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,949
Berkshire Hathaway Energy [Member] | Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14,951
Insurance Corporate And Other [Member]
Disaggregation of Revenue [Line Items]
Other revenue									63,558
Total revenues									$ 63,558

Revenue from contracts with c_2

Revenue from contracts with customers transaction price allocated to remaining performance obligations (Detail) $ in Millions	Dec. 31, 2018USD ($)
Electricity and Natural Gas [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 6,520
Electricity and Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 842
Performance obligations expected to be satisfied, period	1 year
Electricity and Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 5,678
Performance obligations expected to be satisfied, period
Other Sales and Service Contracts [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 3,094
Other Sales and Service Contracts [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 1,190
Performance obligations expected to be satisfied, period	1 year
Other Sales and Service Contracts [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 1,904
Performance obligations expected to be satisfied, period

Pension plans - Net periodic pe

Pension plans - Net periodic pension expense (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of net periodic pension expense
Service cost	$ 271	$ 273	$ 282
Interest cost	593	635	691
Expected return on plan assets	(988)	(939)	(908)
Amortization of actuarial losses and other	188	157	148
Net periodic pension expense	$ 64	$ 126	$ 213

Pension plans - Defined benefit

Pension plans - Defined benefit pension plans - Narrative (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 16,922	$ 18,824	$ 17,750
Amounts recognized in the Consolidated Balance Sheets:
Funded status reflected in assets	510	1,176
Funded status reflected in liabilities	2,473	2,986
Estimated future benefit payments
2,019	1,017
2,020	986
2,021	988
2,022	991
2,023	1,001
2024 - 2028	5,027
Expected contribution to pension plans during the next year	193
Unfunded Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 1,200	$ 1,300

Pension plans - Projected benef

Pension plans - Projected benefit obligation, plan assets and net funded status (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Benefit obligations
Accumulated benefit obligation end of year	$ 15,886	$ 17,524
PBO beginning of year	18,824	17,750
Service cost	271	273	$ 282
Interest cost	593	635	691
Benefits paid	(841)	(897)
Settlements	(434)	(241)
Actuarial (gains) or losses and other	(1,491)	1,304
PBO end of year	16,922	18,824	17,750
Plan assets
Plan assets beginning of year	17,014	15,397
Employer contributions	593	281
Benefits paid	(841)	(897)
Actual return on plan assets	(1,140)	2,136
Settlements	(456)	(235)
Other	(211)	332
Plan assets end of year	14,959	17,014	15,397
Funded status - net liability	1,963	1,810
Berkshire Hathaway Energy [Member]
Benefit obligations
Accumulated benefit obligation end of year	4,346	4,920
PBO beginning of year	5,207	5,077
Service cost	40	47
Interest cost	161	174
Benefits paid	(208)	(271)
Settlements	(301)	(146)
Actuarial (gains) or losses and other	(348)	326
PBO end of year	4,551	5,207	5,077
Plan assets
Plan assets beginning of year	5,129	4,694
Employer contributions	98	122
Benefits paid	(208)	(271)
Actual return on plan assets	(191)	535
Settlements	(324)	(159)
Other	(119)	208
Plan assets end of year	4,385	5,129	4,694
Funded status - net liability	166	78
All Other [Member]
Benefit obligations
Accumulated benefit obligation end of year	11,540	12,604
PBO beginning of year	13,617	12,673
Service cost	231	226
Interest cost	432	461
Benefits paid	(633)	(626)
Settlements	(133)	(95)
Actuarial (gains) or losses and other	(1,143)	978
PBO end of year	12,371	13,617	12,673
Plan assets
Plan assets beginning of year	11,885	10,703
Employer contributions	495	159
Benefits paid	(633)	(626)
Actual return on plan assets	(949)	1,601
Settlements	(132)	(76)
Other	(92)	124
Plan assets end of year	10,574	11,885	$ 10,703
Funded status - net liability	$ 1,797	$ 1,732

Pension plans - Additional tabu

Pension plans - Additional tabular disclosures (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discount rate applicable to pension benefit obligations	3.90%	3.30%	3.80%
Expected long-term rate of return on plan assets	6.40%	6.40%	6.10%
Rate of compensation increase	2.60%	2.80%	3.00%
Discount rate applicable to net periodic pension expense	3.40%	3.90%	4.20%
Amounts recognized in other comprehensive income:
Accumulated other comprehensive income (loss), beginning of year	$ (614)	$ (839)
Amount included in net periodic pension expense	116	155
Actuarial gains (losses) and other	(686)	70
Accumulated other comprehensive income (loss), end of year	$ (1,184)	$ (614)	$ (839)

Pension plans - Fair value of p

Pension plans - Fair value of plan assets (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 14,959	$ 17,014	$ 15,397
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,328	738
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,671	9,824
Government Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,727	1,536
Other Fixed Maturity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	836	799
Investment Funds and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,397	4,117
Quoted Prices (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,692	12,030
Quoted Prices (Level 1) [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,197	594
Quoted Prices (Level 1) [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,499	9,641
Quoted Prices (Level 1) [Member] | Government Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,654	1,497
Quoted Prices (Level 1) [Member] | Other Fixed Maturity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	172	148
Quoted Prices (Level 1) [Member] | Investment Funds and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	170	150
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,899	2,326
Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	131	144
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22	23
Significant Other Observable Inputs (Level 2) [Member] | Government Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	73	39
Significant Other Observable Inputs (Level 2) [Member] | Other Fixed Maturity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	631	619
Significant Other Observable Inputs (Level 2) [Member] | Investment Funds and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,042	1,501
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	456	466
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	150	160
Significant Unobservable Inputs (Level 3) [Member] | Other Fixed Maturity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33	32
Significant Unobservable Inputs (Level 3) [Member] | Investment Funds and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	273	274
Investment Funds and Partnerships at Net Asset Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,912	2,192
Investment Funds and Partnerships at Net Asset Value [Member] | Investment Funds and Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,912	$ 2,192

Pension plans - Defined contrib

Pension plans - Defined contribution pension plans - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan [Abstract]
Contributions to defined contribution plans	$ 1,009	$ 1,001	$ 912

Contingencies and Commitments -

Contingencies and Commitments - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Operating leases, rent expense	$ 1,649	$ 1,579	$ 1,573
Purchase commitments - 2019	15,700
Purchase commitments - 2020	4,500
Purchase commitments - 2021	3,700
Purchase commitments - 2022	3,200
Purchase commitments - 2023	2,900
Purchase commitments - After 2023	17,300
Estimated cost to acquire certain equity ownership interests of less than wholly-owned subsidiaries	$ 5,600

Contingencies and Commitments_2

Contingencies and Commitments - Operating leases minimum payments (Detail) $ in Millions	Dec. 31, 2018USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Future minimum rental payments, 2019	$ 1,360
Future minimum rental payments, 2020	1,317
Future minimum rental payments, 2021	1,098
Future minimum rental payments, 2022	872
Future minimum rental payments, 2023	708
Future minimum rental payments, after 2023	3,658
Future minimum rental payments, total	$ 9,013

Business segment data - Revenue

Business segment data - Revenues (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 63,714	$ 63,450	$ 62,200	$ 58,473	$ 58,800	$ 59,507	$ 57,256	$ 64,370	$ 247,837	$ 239,933	$ 215,114
BNSF [Member]
Segment Reporting Information [Line Items]
Revenues									23,703
Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Revenues									19,970
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									61,770
McLane Company [Member]
Segment Reporting Information [Line Items]
Revenues									49,987
Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									28,849
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									247,587	240,342	215,432
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned									57,418	60,597	45,881
Interest, dividend and other investment income									5,518	4,865	4,522
Revenues									62,936	65,462	50,403
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned									33,363	29,441	25,483
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned									15,944	24,013	14,141
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned									8,111	7,143	6,257
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Revenues									23,855	21,387	19,829
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Revenues									19,987	18,854	17,764
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									61,883	57,645	52,969
Operating Businesses [Member] | McLane Company [Member]
Segment Reporting Information [Line Items]
Revenues									49,987	49,775	48,075
Operating Businesses [Member] | Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									28,939	27,219	26,392
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Revenues									$ 250	$ (409)	$ (318)

Business segment data - Earning

Business segment data - Earnings before income taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Investment and derivative gains/losses	$ (22,455)	$ 2,128	$ 8,304
Interest expense	(3,853)	(4,386)	(3,741)
Equity method investments	(2,167)	3,014	1,109
Earnings before income taxes	4,001	23,838	33,667
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	29,156	21,370	25,408
Interest expense	(3,614)	(4,035)	(3,409)
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	7,513	1,616	6,613
Operating Businesses [Member] | Insurance Group [Member] | Insurance Premiums Earned [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	2,010	(3,239)	2,131
Operating Businesses [Member] | Insurance Group [Member] | Interest, Dividend and Other Investment Income [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	5,503	4,855	4,482
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member] | Insurance Premiums Earned [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	2,449	(310)	462
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member] | Insurance Premiums Earned [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	(1,109)	(3,648)	1,012
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member] | Insurance Premiums Earned [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	670	719	657
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	6,863	6,328	5,693
Interest expense	(1,041)	(1,016)	(992)
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	2,472	2,499	2,878
Interest expense	(1,777)	(2,254)	(1,715)
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	9,366	8,324	7,735
Interest expense	(690)	(679)	(631)
Operating Businesses [Member] | McLane Company [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	246	299	431
Interest expense	(15)	(19)
Operating Businesses [Member] | Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	2,696	2,304	2,058
Interest expense	(91)	(67)	(71)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Investment and derivative gains/losses	(22,455)	2,128	8,304
Interest expense	(458)	(486)	(474)
Equity method investments	(2,167)	3,014	1,109
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	(75)	(2,188)	(680)
Interest expense	$ 219	$ 135	$ 142

Business segment data - Additio

Business segment data - Additional tabular disclosures (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Interest expense		$ 3,853	$ 4,386	$ 3,741
Income tax expense		(321)	(21,515)	9,240
Income tax net benefit - Tax Cuts and Jobs Act of 2017	$ (28,200)		(28,200)
Capital expenditures		14,537	11,708	12,954
Depreciation of tangible assets		7,284	6,968	6,656
Goodwill at year-end	81,258	81,025	81,258	79,486
Total assets	702,095	707,794	702,095	620,854
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense		3,614	4,035	3,409
Income tax expense		5,447	6,030	7,452
Capital expenditures		14,537	11,708	12,954
Depreciation of tangible assets		8,386	7,719	7,411
Goodwill at year-end	81,258	81,025	81,258	79,486
Identifiable assets at year-end	565,423	571,410	565,423	496,824
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Income tax expense		1,374	(71)	1,585
Capital expenditures		130	170	128
Depreciation of tangible assets		79	84	85
Goodwill at year-end	15,499	15,289	15,499	15,474
Identifiable assets at year-end	294,418	289,746	294,418	234,037
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Interest expense		1,041	1,016	992
Income tax expense		1,644	2,369	2,124
Capital expenditures		3,187	3,256	3,819
Depreciation of tangible assets		2,268	2,304	2,079
Goodwill at year-end	14,845	14,851	14,845	14,845
Identifiable assets at year-end	69,438	70,242	69,438	69,277
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Interest expense		1,777	2,254	1,715
Income tax expense		(452)	148	371
Capital expenditures		6,241	4,571	5,090
Depreciation of tangible assets		2,830	2,548	2,560
Goodwill at year-end	9,935	9,851	9,935	9,266
Identifiable assets at year-end	77,710	80,543	77,710	74,571
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense		690	679	631
Income tax expense		2,188	2,678	2,442
Capital expenditures		3,116	2,490	2,581
Depreciation of tangible assets		1,890	1,839	1,757
Goodwill at year-end	33,967	34,019	33,967	32,915
Identifiable assets at year-end	97,753	99,912	97,753	93,835
Operating Businesses [Member] | McLane Company [Member]
Segment Reporting Information [Line Items]
Interest expense		15	19
Income tax expense		59	94	169
Capital expenditures		276	289	258
Depreciation of tangible assets		204	193	165
Goodwill at year-end	734	734	734	734
Identifiable assets at year-end	6,090	6,243	6,090	5,896
Operating Businesses [Member] | Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Interest expense		91	67	71
Income tax expense		634	812	761
Capital expenditures		1,587	932	1,078
Depreciation of tangible assets		1,115	751	765
Goodwill at year-end	6,278	6,281	6,278	6,252
Identifiable assets at year-end	20,014	24,724	20,014	19,208
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Interest expense		458	486	474
Investment and derivative gains/losses, tax		(4,673)	742	1,807
Interest expense, tax		(96)	(170)	(166)
Equity method investments, tax		(753)	910	396
Income tax net benefit - Tax Cuts and Jobs Act of 2017			(28,200)
Goodwill at year-end	81,258	81,025	81,258	79,486
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Interest expense		(219)	(135)	(142)
Income tax expense		(246)	(827)	(249)
Identifiable assets at year-end	$ 55,414	$ 55,359	$ 55,414	$ 44,544

Business segment data - Insuran

Business segment data - Insurance premiums by type (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property/Casualty [Member]
Segment Reporting Information [Line Items]
Premiums written - Direct	$ 44,513	$ 39,377	$ 34,001
Premiums written - Assumed	8,970	17,815	8,037
Premiums written - Ceded	(869)	(694)	(798)
Premiums written	52,614	56,498	41,240
Premiums earned - Direct	43,095	37,755	33,207
Premiums earned - Assumed	8,649	17,813	7,848
Premiums earned - Ceded	(825)	(677)	(843)
Premiums earned	50,919	54,891	40,212
Life/Health [Member]
Segment Reporting Information [Line Items]
Premiums written - Direct	1,111	866	1,060
Premiums written - Assumed	5,540	4,925	4,672
Premiums written - Ceded	(49)	(47)	(62)
Premiums written	6,602	5,744	5,670
Premiums earned - Direct	1,111	866	1,060
Premiums earned - Assumed	5,438	4,866	4,671
Premiums earned - Ceded	(50)	(26)	(62)
Premiums earned	$ 6,499	$ 5,706	$ 5,669

Business segment data - Insur_2

Business segment data - Insurance premiums by geographic area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property/Casualty [Member]
Segment Reporting Information [Line Items]
Premiums written	$ 52,614	$ 56,498	$ 41,240
Property/Casualty [Member] | United States [Member]
Segment Reporting Information [Line Items]
Premiums written	46,146	50,604	35,878
Property/Casualty [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Premiums written	3,726	3,307	3,616
Property/Casualty [Member] | Western Europe [Member]
Segment Reporting Information [Line Items]
Premiums written	2,157	1,516	1,406
Property/Casualty [Member] | All Other Geographic Areas [Member]
Segment Reporting Information [Line Items]
Premiums written	585	1,071	340
Life/Health [Member]
Segment Reporting Information [Line Items]
Premiums written	6,602	5,744	5,670
Life/Health [Member] | United States [Member]
Segment Reporting Information [Line Items]
Premiums written	3,598	3,320	3,473
Life/Health [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Premiums written	1,361	879	715
Life/Health [Member] | Western Europe [Member]
Segment Reporting Information [Line Items]
Premiums written	939	909	822
Life/Health [Member] | All Other Geographic Areas [Member]
Segment Reporting Information [Line Items]
Premiums written	$ 704	$ 636	$ 660

Business segment data - Narrati

Business segment data - Narrative (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues		$ 63,714	$ 63,450	$ 62,200	$ 58,473	$ 58,800	$ 59,507	$ 57,256	$ 64,370	$ 247,837	$ 239,933	$ 215,114
Sales, Service and Leasing Revenues [Member]
Segment Reporting Information [Line Items]
Revenues										$ 139,100	$ 132,800	$ 125,600
United States [Member] | Geographic Concentration [Member] | Sales, Service and Leasing Revenues [Member]
Segment Reporting Information [Line Items]
Concentration percentage										84.00%	85.00%	85.00%
United States [Member] | Geographic Concentration [Member] | Property, Plant and Equipment and Equipment Held for Lease [Member]
Segment Reporting Information [Line Items]
Concentration percentage	89.00%
Walmart Stores, Inc. [Member] | Sales, Service and Leasing Revenues [Member]
Segment Reporting Information [Line Items]
Revenues										$ 13,000	$ 14,000	$ 14,000
Railroad, Utilities and Energy [Member]
Segment Reporting Information [Line Items]
Revenues										$ 43,673	$ 40,005	$ 37,447
Railroad, Utilities and Energy [Member] | United States [Member] | Geographic Concentration [Member] | Revenues [Member]
Segment Reporting Information [Line Items]
Concentration percentage										96.00%	95.00%	95.00%

Quarterly data (Detail)

Quarterly data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information [Line Items]
Revenues	$ 63,714		$ 63,450		$ 62,200		$ 58,473		$ 58,800		$ 59,507		$ 57,256		$ 64,370		$ 247,837	$ 239,933	$ 215,114
Net earnings (loss) attributable to Berkshire shareholders	(25,392)	[1]	18,540	[1]	12,011	[1]	(1,138)	[1]	32,551	[1]	4,067	[1]	4,262	[1]	4,060	[1]	$ 4,021	44,940	$ 24,074
Investment and derivative gains/losses	$ (28,089)		$ 11,660		$ 5,118		$ (6,426)		107		$ 623		$ 143		$ 504
Income tax net benefit - Tax Cuts and Jobs Act of 2017									$ 28,200									$ 28,200
Equivalent Class A [Member]
Quarterly Financial Information [Line Items]
Net earnings (loss) attributable to Berkshire shareholders per equivalent Class A common share	$ (15,467)		$ 11,280		$ 7,301		$ (692)		$ 19,790		$ 2,473		$ 2,592		$ 2,469		$ 2,446	$ 27,326	$ 14,645
[1]	Includes after-tax investment and derivative gains/losses and a one-time income tax net benefit attributable to the enactment of the Tax Cuts and Jobs Act of 2017 as follows: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Investment and derivative gains/losses - 2018 $ (6,426) $ 5,118 $ 11,660 $ (28,089) Investment and derivative gains/losses - 2017 504 143 623 107 Income tax net benefit - Tax Cuts and Jobs Act of 2017 - - - 28,200

Condensed Financial Informati_2

Condensed Financial Information - Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets:
Total assets	$ 707,794	$ 702,095	$ 620,854
Liabilities and Shareholders' Equity:
Income taxes, principally deferred	51,375	56,607
Total liabilities	355,294	350,141
Berkshire Hathaway shareholders' equity	348,703	348,296
Total liabilities and shareholders' equity	707,794	702,095
Berkshire Hathaway Inc. (Parent) [Member]
Assets:
Cash and cash equivalents	3,437	4,039	$ 3,221	$ 10,609
Short-term investments in U.S. Treasury Bills	22,957	13,132
Investments in and advances to/from consolidated subsidiaries	328,898	335,668
Investment in The Kraft Heinz Company	13,813	17,635
Other assets	80	79
Total assets	369,185	370,553
Liabilities and Shareholders' Equity:
Accounts payable, accrued interest and other liabilities	1,507	196
Income taxes, principally deferred	2,104	3,294
Notes payable and other borrowings	16,871	18,767
Total liabilities	20,482	22,257
Berkshire Hathaway shareholders' equity	348,703	348,296
Total liabilities and shareholders' equity	$ 369,185	$ 370,553

Condensed Financial Informati_3

Condensed Financial Information - Statements of Earnings and Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
From consolidated subsidiaries:
Investment gains (losses)																	$ (22,155)	$ 1,410	$ 7,553
Equity method earnings (losses)																	(2,167)	3,014	1,109
Total revenues	$ 63,714		$ 63,450		$ 62,200		$ 58,473		$ 58,800		$ 59,507		$ 57,256		$ 64,370		247,837	239,933	215,114
Cost and expense items:
Interest expense																	3,853	4,386	3,741
Income tax expense (benefit)																	(321)	(21,515)	9,240
Total costs and expenses																	219,214	221,237	190,860
Net earnings attributable to Berkshire Hathaway shareholders	$ (25,392)	[1]	$ 18,540	[1]	$ 12,011	[1]	$ (1,138)	[1]	$ 32,551	[1]	$ 4,067	[1]	$ 4,262	[1]	$ 4,060	[1]	4,021	44,940	24,074
Comprehensive income attributable to Berkshire Hathaway shareholders																	1,810	66,213	27,390
Berkshire Hathaway Inc. (Parent) [Member]
From consolidated subsidiaries:
Dividends																	9,658	5,367	9,862
Undistributed earnings (losses)																	(3,952)	37,832	13,264
Total income from consolidated subsidiaries																	5,706	43,199	23,126
Investment gains (losses)																	(4)	(1)	700
Equity method earnings (losses)																	(2,730)	2,938	923
Other income																	649	350	262
Total revenues																	3,621	46,486	25,011
Cost and expense items:
General and administrative																	216	159	80
Interest expense																	601	522	452
Foreign exchange (gains) losses Euro-denominated senior notes																	(366)	1,008	(244)
Income tax expense (benefit)																	(851)	(143)	649
Total costs and expenses																	(400)	1,546	937
Net earnings attributable to Berkshire Hathaway shareholders																	4,021	44,940	24,074
Other comprehensive income attributable to Berkshire Hathaway shareholders																	(2,211)	21,273	3,316
Comprehensive income attributable to Berkshire Hathaway shareholders																	$ 1,810	$ 66,213	$ 27,390
[1]	Includes after-tax investment and derivative gains/losses and a one-time income tax net benefit attributable to the enactment of the Tax Cuts and Jobs Act of 2017 as follows: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Investment and derivative gains/losses - 2018 $ (6,426) $ 5,118 $ 11,660 $ (28,089) Investment and derivative gains/losses - 2017 504 143 623 107 Income tax net benefit - Tax Cuts and Jobs Act of 2017 - - - 28,200

Condensed Financial Informati_4

Condensed Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net earnings attributable to Berkshire Hathaway shareholders	$ (25,392)	[1]	$ 18,540		$ 12,011		$ (1,138)	[1]	$ 32,551	[1]	$ 4,067		$ 4,262		$ 4,060	[1]	$ 4,021	$ 44,940	$ 24,074
Adjustments to reconcile net earnings to cash flows from operating activities:
Investment gains (losses)																	22,155	(1,410)	(7,553)
Income taxes payable																	(4,957)	(24,957)	4,044
Other																	2,957	458	(161)
Net cash flows from operating activities																	37,400	45,728	32,647
Cash flows from investing activities:
Net cash flows from investing activities																	(32,849)	(41,009)	(84,225)
Cash flows from financing activities:
Acquisition of treasury stock																	(1,346)
Other																	(343)	(121)	112
Net cash flows from financing activities																	(5,812)	(1,398)	12,791
Other cash flow information:
Income taxes paid																	4,354	3,286	4,719
Berkshire Hathaway Inc. (Parent) [Member]
Cash flows from operating activities:
Net earnings attributable to Berkshire Hathaway shareholders																	4,021	44,940	24,074
Adjustments to reconcile net earnings to cash flows from operating activities:
Investment gains (losses)																	4	1	(700)
Undistributed earnings of consolidated subsidiaries																	3,952	(37,832)	(13,264)
Income taxes payable																	(972)	(135)	629
Other																	3,062	(1,234)	(161)
Net cash flows from operating activities																	10,067	5,740	10,578
Cash flows from investing activities:
Redemption of Kraft Heinz Company preferred stock																			8,320
Investments in and advances to/from consolidated subsidiaries, net																	460	(239)	(26,398)
Purchases of U.S. Treasury Bills																	(29,740)	(19,663)	(9,350)
Sales and maturities of U.S. Treasury Bills																	21,442	14,847	1,145
Net cash flows from investing activities																	(7,838)	(5,055)	(26,283)
Cash flows from financing activities:
Proceeds from borrowings																	17	1,201	9,278
Repayments of borrowings																	(1,563)	(1,145)	(1,125)
Acquisition of treasury stock																	(1,346)
Other																	61	77	164
Net cash flows from financing activities																	(2,831)	133	8,317
Increase (decrease) in cash and cash equivalents																	(602)	818	(7,388)
Cash and cash equivalents at beginning of year							$ 4,039								$ 3,221		4,039	3,221	10,609
Cash and cash equivalents at end of year	$ 3,437								$ 4,039								3,437	4,039	3,221
Other cash flow information:
Income taxes paid																	2,790	2,076	3,583
Interest paid																	$ 388	$ 386	$ 307
[1]	Includes after-tax investment and derivative gains/losses and a one-time income tax net benefit attributable to the enactment of the Tax Cuts and Jobs Act of 2017 as follows: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Investment and derivative gains/losses - 2018 $ (6,426) $ 5,118 $ 11,660 $ (28,089) Investment and derivative gains/losses - 2017 504 143 623 107 Income tax net benefit - Tax Cuts and Jobs Act of 2017 - - - 28,200

Note to Condensed Financial Inf

Note to Condensed Financial Information - Narrative (Detail) € in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2018EUR (€)	Dec. 31, 2017EUR (€)
Condensed Financial Statements, Captions [Line Items]
Debt maturities: 2019		$ 12,212
Debt maturities: 2020		5,589
Debt maturities: 2021		5,521
Debt maturities: 2022		4,962
Debt maturities: 2023		9,437
Income tax net benefit - Tax Cuts and Jobs Act of 2017	$ 28,200		$ 28,200
Berkshire Hathaway Inc. (Parent) [Member]
Condensed Financial Statements, Captions [Line Items]
Debt maturities: 2019		752
Debt maturities: 2020		1,149
Debt maturities: 2021		2,131
Debt maturities: 2022		613
Debt maturities: 2023		3,991
Guarantee of subsidiary debt obligations		$ 12,400
Income tax net benefit - Tax Cuts and Jobs Act of 2017			$ 550
Berkshire Hathaway Inc. (Parent) [Member] | Heinz Holding Company [Member]
Condensed Financial Statements, Captions [Line Items]
Equity method investment ownership percentage after transactions					50.00%
Berkshire Hathaway Inc. (Parent) [Member] | The Kraft Heinz Company [Member]
Condensed Financial Statements, Captions [Line Items]
Equity method investment ownership percentage after transactions		26.70%		26.80%
Berkshire Hathaway Inc. (Parent) [Member] | Euro Denominated [Member]
Condensed Financial Statements, Captions [Line Items]
Principal amount of debt issued | €						€ 6,850	€ 6,850