Berkshire Hathaway (BRK-B) 10-Q 7 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	BRKA
Entity Registrant Name	BERKSHIRE HATHAWAY INC.
Entity Central Index Key	1,067,983
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		747,677
Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,346,076,963

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018		Dec. 31, 2017
ASSETS
Investments in fixed maturity securities	$ 19,920		$ 21,353
Investments in equity securities	172,976	[1]	170,540	[2]
Inventories	16,244		16,187
Goodwill	81,337		81,258
Deferred charges under retroactive reinsurance contracts	15,007		15,278
Total assets	702,651		702,095
LIABILITIES
Income taxes, principally deferred	55,718		56,607
Unpaid losses and loss adjustment expenses	62,094		61,122
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts	42,344		42,937
Total liabilities	351,599		350,141
Shareholders' equity:
Common stock	8		8
Capital in excess of par value	35,681		35,694
Accumulated other comprehensive income	(2,477)		58,571
Retained earnings	315,952		255,786
Treasury stock, at cost	(1,763)		(1,763)
Berkshire Hathaway shareholders' equity	347,401		348,296
Noncontrolling interests	3,651		3,658
Shareholders' equity	351,052		351,954
Total liabilities and shareholders' equity	702,651		702,095
Insurance and Other [Member]
ASSETS
Cash and cash equivalents	50,559		25,460
Short-term investments in U.S. Treasury Bills	48,040		78,515
Investments in fixed maturity securities	19,920		21,353
Investments in equity securities	166,658		164,026
Investment in The Kraft Heinz Company (Fair Value: 2018 - $20,272; 2017 - $25,306)	17,687		17,635
Receivables	30,906		28,578
Inventories	16,244		16,187
Property, plant and equipment	23,807		20,104
Goodwill	55,079		54,985
Other intangible assets	32,260		32,518
Deferred charges under retroactive reinsurance contracts	15,007		15,278
Other	11,939		11,158
Total assets	488,106		485,797
LIABILITIES
Unpaid losses and loss adjustment expenses	62,094		61,122
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts	42,344		42,937
Unearned premiums	18,448		16,040
Life, annuity and health insurance benefits	17,935		17,608
Other policyholder liabilities	7,864		7,654
Accounts payable, accruals and other liabilities	25,782		23,099
Notes payable and other borrowings	25,663		27,324
Total liabilities	200,130		195,784
Railroad, Utilities and Energy [Member]
ASSETS
Cash and cash equivalents	3,550		2,910
Property, plant and equipment	128,385		128,184
Goodwill	24,766		24,780
Regulatory assets	2,987		2,950
Other	15,394		15,589
Total assets	175,082		174,413
LIABILITIES
Accounts payable, accruals and other liabilities	10,786		11,334
Regulatory liabilities	7,599		7,511
Notes payable and other borrowings	62,667		62,178
Total liabilities	81,052		81,023
Finance and Financial Products [Member]
ASSETS
Cash and cash equivalents	3,772		3,213
Short-term investments in U.S. Treasury Bills	2,641		5,856
Loans and finance receivables	13,845		13,748
Property, plant and equipment and assets held for lease	9,920		9,931
Goodwill	1,492		1,493
Other	7,793		7,644
Total assets	39,463		41,885
LIABILITIES
Accounts payable, accruals and other liabilities	1,566		1,470
Derivative contract liabilities	2,378		2,172
Notes payable and other borrowings	10,755		13,085
Total liabilities	$ 14,699		$ 16,727
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.1 billion; Apple Inc. - $40.7 billion; Bank of America Corporation - $21.0 billion; The Coca-Cola Company - $17.4 billion and Wells Fargo & Company - $25.2 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).

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Insurance and Other [Member]
Investment in The Kraft Heinz Company, Fair Value	$ 20,272	$ 25,306

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenues:
Sales and service revenues		$ 41,509
Total revenues		58,473	$ 64,370
Investment and derivative contract gains/losses:
Investments gains (losses)		(7,809)	315
Derivative contract gains (losses)		(206)	460
Investment and derivative gains/losses		(8,015)	775
Costs and expenses:
Total costs and expenses		52,382	59,738
Earnings (loss) before income taxes and equity method earnings		(1,924)	5,407
Equity method earnings		401	281
Earnings (loss) before income taxes		(1,523)	5,688
Income tax expense (benefit)		(452)	1,549
Net earnings (loss)		(1,071)	4,139
Earnings attributable to noncontrolling interests		67	79
Net earnings (loss) attributable to Berkshire Hathaway shareholders		$ (1,138)	$ 4,060
Equivalent Class A [Member]
Net earnings (loss) per share attributable to Berkshire Hathaway shareholders:
Net earnings (loss) per share attributable to Berkshire Hathaway shareholders		$ (692)	$ 2,469
Average equivalent shares outstanding		1,644,958	1,644,425
Equivalent Class B [Member]
Net earnings (loss) per share attributable to Berkshire Hathaway shareholders:
Net earnings (loss) per share attributable to Berkshire Hathaway shareholders	[1]	$ (0.46)	$ 1.65
Average equivalent shares outstanding		2,467,436,888	2,466,636,938
Insurance and Other [Member]
Revenues:
Insurance premiums earned		$ 13,373	$ 21,753
Sales and service revenues		31,623	30,229
Interest, dividend and other investment income		1,315	1,162
Total revenues		46,311	53,144
Costs and expenses:
Insurance losses and loss adjustment expenses		8,963	18,566
Life, annuity and health insurance benefits		1,287	1,227
Insurance underwriting expenses		2,604	2,339
Cost of sales and services		25,415	24,360
Selling, general and administrative expenses		4,024	4,116
Interest expense		390	270
Total costs and expenses		42,683	50,878
Railroad, Utilities and Energy [Member]
Revenues:
Total revenues		10,102	9,378
Costs and expenses:
Cost of sales and operating expenses		7,401	6,754
Interest expense		710	693
Total costs and expenses		8,111	7,447
Finance and Financial Products [Member]
Revenues:
Sales and service revenues		1,693	1,498
Interest, dividend and other investment income		367	350
Total revenues		2,060	1,848
Costs and expenses:
Cost of sales and services		1,029	867
Selling, general and administrative expenses		467	442
Interest expense		92	104
Total costs and expenses		$ 1,588	$ 1,413
[1]	Net earnings (loss) per average equivalent Class B share outstanding are one-fifteen-hundredth of the equivalent Class A amount.

Consolidated Statements of Ear5

Consolidated Statements of Earnings (Parenthetical)	3 Months Ended
	Mar. 31, 2018
Class B [Member]
Ratio of earnings per Class B share to earnings per Class A share	0.000667

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ (1,071)	$ 4,139
Other comprehensive income:
Net change in unrealized appreciation of investments	(45)	8,377
Applicable income taxes	(2)	(2,872)
Reclassification of investment appreciation in net earnings	(221)	(305)
Applicable income taxes	46	107
Foreign currency translation	601	558
Applicable income taxes	(6)	(69)
Prior service cost and actuarial gains/losses of defined benefit pension plans	(24)	(10)
Applicable income taxes	17	7
Other, net	(31)	3
Other comprehensive income, net	335	5,796
Comprehensive income	(736)	9,935
Comprehensive income attributable to noncontrolling interests	75	103
Comprehensive income attributable to Berkshire Hathaway shareholders	$ (811)	$ 9,832

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, 2016	$ 285,428	$ 35,689	$ 37,298	$ 210,846	$ (1,763)	$ 3,358
Net earnings (loss)	4,139			4,060		79
Other comprehensive income, net	5,796		5,772			24
Issuance of common stock	34	34
Transactions with noncontrolling interests	(48)	(16)				(32)
Ending Balance at Mar. 31, 2017	295,349	35,707	43,070	214,906	(1,763)	3,429
Beginning Balance at Dec. 31, 2017	351,954	35,702	58,571	255,786	(1,763)	3,658
Adoption of new accounting pronouncements	(71)		(61,375)	61,304
Net earnings (loss)	(1,071)			(1,138)		67
Other comprehensive income, net	335		327			8
Issuance of common stock	24	24
Transactions with noncontrolling interests	(119)	(37)				(82)
Ending Balance at Mar. 31, 2018	$ 351,052	$ 35,689	$ (2,477)	$ 315,952	$ (1,763)	$ 3,651

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net earnings (loss)	$ (1,071)	$ 4,139
Adjustments to reconcile net earnings (loss) to operating cash flows:
Investment gains/losses	7,809	(315)
Depreciation and amortization	2,387	2,243
Other	(1)	120
Changes in operating assets and liabilities:
Losses and loss adjustment expenses	69	16,900
Deferred charges reinsurance assumed	271	(5,783)
Unearned premiums	2,352	1,829
Receivables and originated loans	(2,186)	(1,197)
Other assets	(881)	(339)
Other liabilities	(392)	(753)
Income taxes	(801)	1,451
Net cash flows from operating activities	7,556	18,295
Cash flows from investing activities:
Purchases of U.S. Treasury Bills and fixed maturity securities	(13,037)	(45,342)
Purchases of equity securities	(14,765)	(10,590)
Sales of U.S. Treasury Bills and fixed maturity securities	13,577	10,048
Redemptions and maturities of U.S. Treasury Bills and fixed maturity securities	35,088	23,990
Sales and redemptions of equity securities	4,240	3,452
Purchases of loans and finance receivables	(41)	(52)
Collections of loans and finance receivables	100	97
Acquisitions of businesses, net of cash acquired	(112)	(1,599)
Purchases of property, plant and equipment	(2,589)	(2,355)
Other	(153)	(181)
Net cash flows from investing activities	22,308	(22,532)
Cash flows from financing activities:
Changes in short term borrowings, net	(1,929)	87
Other	(102)	(23)
Net cash flows from financing activities	(3,794)	2,015
Effects of foreign currency exchange rate changes	92	61
Increase (decrease) in cash and cash equivalents and restricted cash	26,162	(2,161)
Cash and cash equivalents and restricted cash:
Cash and cash equivalents and restricted cash at beginning of year	32,212	28,643
Cash and cash equivalents and restricted cash at end of first quarter	58,374	26,482
Restricted cash, included in other assets at beginning of year	629	595
Restricted cash, included in other assets at end of first quarter	493	519
Insurance and Other [Member]
Cash flows from financing activities:
Proceeds from borrowings	17	1,203
Repayments of borrowings	(1,840)	(1,130)
Cash and cash equivalents and restricted cash:
Cash and cash equivalents at beginning of year	25,460	23,581
Cash and cash equivalents at end of first quarter	50,559	18,362
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	3,613	2,094
Repayments of borrowings	(1,221)	(446)
Cash and cash equivalents and restricted cash:
Cash and cash equivalents at beginning of year	2,910	3,939
Cash and cash equivalents at end of first quarter	3,550	5,584
Finance and Financial Products [Member]
Cash flows from financing activities:
Proceeds from borrowings	20	1,298
Repayments of borrowings	(2,352)	(1,068)
Cash and cash equivalents and restricted cash:
Cash and cash equivalents at beginning of year	3,213	528
Cash and cash equivalents at end of first quarter	$ 3,772	$ 2,017

General

General	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
General	Note 1. General The accompanying unaudited Consolidated Financial Statements include the accounts of Berkshire Hathaway Inc. (“Berkshire” or “Company”) consolidated with the accounts of all its subsidiaries and affiliates in which Berkshire holds controlling financial interests as of the financial statement date. In these notes, the terms “us,” “we” or “our” refer to Berkshire and its consolidated subsidiaries. Reference is made to Berkshire’s most recently issued Annual Report on Form 10-K Financial information in this Quarterly Report reflects all adjustments (consisting only of normal recurring adjustments) that are, in the opinion of management, necessary to a fair statement of results for the interim periods in accordance with accounting principles generally accepted in the United States (“GAAP”). For a number of reasons, our results for interim periods are not normally indicative of results to be expected for the year. The timing and magnitude of catastrophe losses incurred by insurance subsidiaries and the estimation error inherent to the process of determining liabilities for unpaid losses of insurance subsidiaries can be more significant to results of interim periods than to results for a full year. Changes in market prices of the equity securities we own can produce significant effects on our consolidated shareholders’ equity. Beginning in 2018, those effects are included in our Consolidated Statements of Earnings, whereas in pre-2018

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	Note 2. New Accounting Pronouncements On January 1, 2018, we adopted Accounting Standards Update (“ASU”) 2016-01 2016-01”), 2018-02 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 ) (71 ) 61,304 Shareholders’ equity — — (71 ) (71 ) With respect to ASU 2016-01, after-tax 2016-01 available-for-sale We also reclassified the stranded deferred income taxes in accumulated other comprehensive income as of January 1, 2018 to retained earnings in connection with our adoption of ASU 2018-02. We adopted ASC 606 using the modified retrospective method, whereby the cumulative effect of the adoption was recorded as an adjustment to retained earnings. Prior year financial statements were not restated. The initial adoption of ASC 606 resulted in an increase to both assets (primarily property, plant and equipment) and other liabilities and a relatively minor reduction in retained earnings as of the beginning of 2018. ASC 606 also provides for certain other disclosures which are included in Note 3. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02 2016-02 right-of-use 2016-02 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

Revenues from contracts with cu

Revenues from contracts with customers	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues from contracts with customers	Note 3. Revenues from contracts with customers As discussed in Note 2, we adopted ASC 606 “Revenues from Contracts with Customers” on January 1, 2018. Our revenue recognition practices under ASC 606 do not differ materially 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. Our accounting policies related to revenue from contracts with customers follow. We manufacture and/or distribute a wide variety of industrial, building and consumer products. Our sales contracts provide customers with manufactured products and goods acquired for resale 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 expected consideration to each obligation based on the relative stand-alone selling prices of each product or service. Expected consideration (and therefore revenue) reflects reductions for returns, allowances, volume discounts and other incentives, some of which may be contingent on future events. In certain customer contracts of our grocery distribution business, consideration 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. Expected consideration excludes sales and value-added taxes collected on behalf of taxing authorities. 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 fulfillment activities. Our product sales revenues are predominantly 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, given the 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 bodies. 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 recognized are equivalent to the amounts we have the right to invoice as it corresponds directly with the value to the customer of the performance to date and includes billed and unbilled amounts. As of March 31, 2018 and December 31, 2017, trade receivables, net included in other assets on the Consolidated Balance Sheets relate substantially to customer revenue, and includes unbilled revenue of $582 million and $665 million, respectively. 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. Service revenues mainly derive from contracts with customers in which performance obligations are satisfied over time, including instances where customers receive and consume benefits as we perform the services. Revenues under such contracts are recorded over time. Service revenues primarily derive from contracts for freight rail transportation, real estate brokerage, automotive repair, aircraft management, aviation training and news distribution services. 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 for its customers. 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 thirty 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 Prior to January 1, 2018, we recognized revenues from the sales of fractional ownership interests in aircraft over the terms 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 minimum commitment period. ASC 606 provides that such contracts are subject to accounting guidance for lease contracts and not ASC 606. The principal effects of this re-characterization re-categorization The following table summarizes customer contract revenues disaggregated by reportable segment and the source of the revenue for the three months ended March 31, 2018 (in millions). Other revenues included in our consolidated revenues were primarily insurance premiums earned, interest, dividend and other investment income and lease income which are not within the scope of ASC 606. Manufacturing McLane Service and BNSF Berkshire Finance and Insurance, Total Manufactured products: Industrial and commercial products $ 6,393 $ — $ 54 $ — $ — $ 161 $ — $ 6,608 Building products 2,919 — — — — 1 — 2,920 Consumer products 2,848 — — — — 848 — 3,696 Grocery and convenience store distribution — 8,512 — — — — — 8,512 Food and beverage distribution — 3,643 — — — — — 3,643 Auto sales — — 1,931 — — — — 1,931 Other retail and wholesale distribution 496 — 2,694 — — 20 — 3,210 Service 218 17 942 5,580 700 8 — 7,465 Electricity and natural gas — — — — 3,524 — — 3,524 Total 12,874 12,172 5,621 5,580 4,224 1,038 — 41,509 Other revenue 38 17 939 10 288 1,022 14,650 16,964 $ 12,912 $ 12,189 $ 6,560 $ 5,590 $ 4,512 $ 2,060 $ 14,650 $ 58,473 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 March 31, 2018 follows (in millions). Such contracts relate to our utilities and energy businesses. Performance obligations Less than Greater than Total Electricity and natural gas $ 1,007 $ 4,352 $ 5,359

Investments in fixed maturity s

Investments in fixed maturity securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments in fixed maturity securities	Note 4. Investments in fixed maturity securities Investments in securities with fixed maturities as of March 31, 2018 and December 31, 2017 are summarized by type below (in millions). Amortized Unrealized Unrealized Fair March 31, 2018 U.S. Treasury, U.S. government corporations and agencies $ 3,633 $ 11 $ (36 ) $ 3,608 States, municipalities and political subdivisions 737 30 (8 ) 759 Foreign governments 7,837 83 (32 ) 7,888 Corporate bonds 6,308 519 (8 ) 6,819 Mortgage-backed securities 761 88 (3 ) 846 $ 19,276 $ 731 $ (87 ) $ 19,920 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 government securities include securities issued by national and provincial government entities as well as instruments that are unconditionally guaranteed by such entities. As of March 31, 2018, approximately 89% of 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 securities with fixed maturities at March 31, 2018 are summarized below by contractual maturity dates. Actual maturities may differ from contractual maturities due to early call or prepayment rights held by issuers. Amounts are in millions. Due in one Due after one Due after five Due after Mortgage- Total Amortized cost $ 7,178 $ 9,884 $ 460 $ 993 $ 761 $ 19,276 Fair value 7,227 9,982 515 1,350 846 19,920

Investments in equity securitie

Investments in equity securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments in equity securities	Note 5. Investments in equity securities Investments in equity securities as of March 31, 2018 and December 31, 2017 are summarized based on the primary industry of the investee in the table below (in millions). Cost Basis Net Unrealized Gains Fair Value March 31, 2018 Banks, insurance and finance $ 25,986 $ 50,091 $ 76,077 Consumer products 38,130 23,864 61,994 Commercial, industrial and other 21,714 13,191 34,905 $ 85,830 $ 87,146 $ 172,976 * Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company – $14.1 billion; Apple Inc. – $40.7 billion; Bank of America Corporation – $21.0 billion; The Coca-Cola Company – $17.4 billion and Wells Fargo & Company – $25.2 billion). Cost Basis Net Unrealized Gains Fair Value 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). Investments in equity securities are reflected in our Consolidated Balance Sheets as follows (in millions). March 31, 2018 December 31, 2017 Insurance and other $ 166,658 $ 164,026 Railroad, utilities and energy * 1,755 1,961 Finance and financial products * 4,563 4,553 $ 172,976 $ 170,540 * Included in other assets.

Equity Method Investments

Equity Method Investments	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Note 6. Equity Method Investments Berkshire holds 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. The carrying value of this investment was approximately $17.7 billion at March 31, 2018 and $17.6 billion at December 31, 2017. Our earnings determined under the equity method during the first quarter of 2018 were $265 million and $239 million in the first quarter of 2017. We received dividends on the common stock of $203 million during the first quarter of 2018 and $195 million in 2017, which we recorded as reductions of our investment. Summarized consolidated financial information of Kraft Heinz follows (in millions). March 31, 2018 December 30, 2017 Assets $ 120,787 $120,232 Liabilities 54,324 53,985 First Quarter 2018 2017 Sales $ 6,304 $ 6,324 Net earnings attributable to Kraft Heinz common shareholders $ 993 $ 893 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 (“ETT”). Our investments in these entities were approximately $3.5 billion as of March 31, 2018 and $3.4 billion as of December 31, 2017 and were included in other assets. Our equity method earnings in these entities for the first quarter were $136 million in 2018 and $42 million in 2017. Additional information concerning these investments follows. We own a 50% interest in Berkadia, with Leucadia National Corporation (“Leucadia”) 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. We support the commercial paper with a surety policy issued by a Berkshire insurance subsidiary. Leucadia 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 27,000 team members, 750 locations across the U.S. and Canada, and approximately $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.

Income taxes

Income taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes	Note 7. Income taxes Our consolidated effective income tax rates for the first quarter of 2018 and 2017 were 29.7% and 27.2%, respectively. Our effective income tax rate normally reflects recurring benefits from: (a) dividends received deductions applicable to certain investments in equity securities and (b) income production tax credits related to wind-powered electricity generation placed in service in the U.S. In 2018, our effective income tax rate reflects the U.S. statutory rate of 21%, while the rate for 2017 reflects the U.S. statutory rate of 35%. Our periodic effective income tax rate is also affected by the relative mix of pre-tax In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin 118 (“SAB 118”) to provide clarification in implementing the Tax Cuts and Jobs Act of 2017 (“TCJA”) when registrants do not have the necessary information available to complete the accounting for an element of the TCJA in the period of its enactment. SAB 118 provides for tax amounts to be classified as provisional and subject to remeasurement for up to one year from the enactment date for such elements when the accounting effect is not complete, but can be reasonably estimated. We consider our estimate of the tax on accumulated undistributed earnings of foreign subsidiaries to be provisional and subject to remeasurement when we obtain the necessary additional information to complete the accounting. While we believe our estimate is reasonable, it will take additional time to validate the inputs to the foreign earnings and profits calculations, the basis on which the repatriation tax is determined, and how the applicable states will address the U.S. repatriation tax. We currently expect that our accounting for the repatriation tax under the TCJA will be completed by the end of 2018.

Investment gains_losses

Investment gains/losses	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investment gains/losses	Note 8. Investment gains/losses A summary of investment gains and losses in the first quarter of 2018 and 2017 follows (in millions). 2018 2017 Equity securities: Investment gains and losses during 2018 on securities sold in 2018 $ (240) $ — Unrealized investment gains and losses on securities held at the end of the period (7,807) — Gross realized gains — 425 Gross realized losses — (125 ) (8,047) 300 Fixed maturity securities: Gross realized gains 359 11 Gross realized losses (138) (6 ) Other 17 10 $(7,809) $ 315 We recognize investment gains and losses when we sell or otherwise dispose of such securities. Beginning in 2018, equity security investment gains and losses also include unrealized gains and losses from changes in market prices during the period. See Note 2. Prior to 2018, we recorded the changes in unrealized gains and losses on our investments in equity securities in other comprehensive income.

Receivables

Receivables	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Receivables	Note 9. Receivables Receivables of insurance and other businesses are comprised of the following (in millions). March 31, 2018 December 31, 2017 Insurance premiums receivable $ 12,570 $ 11,058 Reinsurance recoverable on unpaid losses 3,048 3,201 Trade receivables 12,568 11,756 Other 3,078 2,925 Allowances for uncollectible accounts (358) (362) $ 30,906 $ 28,578 A summary of loans and finance receivables of our finance and financial products businesses follows (in millions). March 31, December 31, 2017 Loans and finance receivables before allowances and discounts $ 14,209 $ 14,126 Allowances for uncollectible loans (179) (180) Unamortized acquisition discounts (185) (198) $ 13,845 $ 13,748 Loans and finance receivables are predominantly installment loans originated or acquired by our manufactured housing business. Provisions for loan losses in the first quarter of 2018 and 2017 were $34 million and $38 million, respectively. Loan charge-offs, net of recoveries, in the first quarter were $35 million in 2018 and $43 million in 2017. At March 31, 2018, approximately 98% of the loan balances were evaluated collectively for impairment. As part of the evaluation process, credit quality indicators are reviewed and loans are designated as performing or non-performing. one-year

Inventories

Inventories	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventories	Note 10. Inventories Inventories are comprised of the following (in millions). March 31, 2018 December 31, 2017 Raw materials $ 3,094 $ 2,997 Work in process and other 2,228 2,315 Finished manufactured goods 4,188 4,179 Goods acquired for resale 6,734 6,696 $ 16,244 $ 16,187

Property, plant and equipment a

Property, plant and equipment and assets held for lease	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property, plant and equipment and assets held for lease	Note 11. Property, plant and equipment and assets held for lease A summary of property, plant and equipment of our insurance and other businesses follows (in millions). In conjunction with the adoption of ASC 606, we recorded a net asset of approximately $3.5 billion in aircraft sold under fractional aircraft ownership programs in machinery and equipment. Such amount consisted of cost of approximately $5.3 billion and accumulated depreciation of $1.8 billion. We also recorded other liabilities of approximately $3.5 billion for estimated repurchase obligations and unearned lease revenues, substantially offsetting the amount recorded in machinery and equipment. See Note 2. March 31, 2018 December 31, 2017 Land $ 2,310 $ 2,292 Buildings and improvements 8,961 8,810 Machinery and equipment 27,707 21,935 Furniture, fixtures and other 4,493 4,387 43,471 37,424 Accumulated depreciation (19,664 ) (17,320 ) $ 23,807 $20,104 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. March 31, 2018 December 31, 2017 Railroad: Land $ 6,090 $ 6,088 Track structure and other roadway 51,652 51,320 Locomotives, freight cars and other equipment 12,600 12,543 Construction in progress 943 989 71,285 70,940 Accumulated depreciation (8,954 ) (8,627 ) 62,331 62,313 Utilities and energy: Utility generation, transmission and distribution systems 75,068 74,660 Interstate natural gas pipeline assets 7,230 7,176 Independent power plants and other assets 7,622 7,499 Construction in progress 2,735 2,556 92,655 91,891 Accumulated depreciation (26,601 ) (26,020 ) 66,054 65,871 $ 128,385 $ 128,184 Assets held for lease and property, plant and equipment of our finance and financial products businesses are summarized below (in millions). Assets held for lease includes railcars, intermodal tank containers, cranes, over-the-road March 31, 2018 December 31, 2017 Assets held for lease $ 12,337 $ 12,318 Land 232 231 Buildings, machinery and other 1,464 1,444 14,033 13,993 Accumulated depreciation (4,113 ) (4,062 ) $ 9,920 $ 9,931 A summary of depreciation expense for the first quarters of 2018 and 2017 follows (in millions). First Quarter 2018 2017 Insurance and other $ 649 $ 542 Railroad, utilities and energy 1,225 1,175 Finance and financial products 161 159 $ 2,035 $ 1,876

Goodwill and other intangible a

Goodwill and other intangible assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and other intangible assets	Note 12. Goodwill and other intangible assets A reconciliation of the change in the carrying value of goodwill is as follows (in millions). March 31, December 31, Balance at beginning of year $ 81,258 $ 79,486 Acquisitions of businesses 52 1,545 Other, including foreign currency translation 27 227 Balance at end of period $ 81,337 $ 81,258 Other intangible assets are summarized as follows (in millions). March 31, 2018 December 31, 2017 Gross carrying amount Accumulated Gross carrying Accumulated Insurance and other $ 40,317 $ 8,057 $ 40,225 $ 7,707 Railroad, utilities and energy 993 334 988 324 $ 41,310 $ 8,391 $ 41,213 $ 8,031 Trademarks and trade names $ 5,394 $ 710 $ 5,381 $ 692 Patents and technology 4,383 2,579 4,341 2,493 Customer relationships 28,353 3,943 28,322 3,722 Other 3,180 1,159 3,169 1,124 $ 41,310 $ 8,391 $ 41,213 $ 8,031 Amortization expense in the first quarter was $352 million in 2018 and $367 million in 2017. Intangible assets with indefinite lives were approximately $18.9 billion as of March 31, 2018 and December 31, 2017.

Derivative contracts

Derivative contracts	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative contracts	Note 13. Derivative contracts We are party to derivative contracts primarily through our finance and financial products and our utilities and energy businesses. Currently, the derivative contracts of our finance and financial products businesses consist of equity index put option contracts written between 2004 and 2008. The liabilities and related notional values of such contracts follows (in millions). March 31, 2018 December 31, 2017 Liabilities Notional Value Liabilities Notional Value Equity index put options $ 2,378 $ 29,479 (1) $ 2,172 $ 28,753 (1) (1) 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 record derivative contract liabilities at fair value and include the changes in the fair values of such contracts in earnings as derivative contract gains/losses. A summary of derivative contract gains/losses included in our Consolidated Statements of Earnings in the first quarter of 2018 and 2017 follows (in millions). First Quarter 2018 2017 Equity index put options $ (206 ) $ 460 The equity index put option contracts are European style options written prior to March 2008 on four major equity indexes. The contracts expire between June 2018 and January 2026. 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 $4.2 billion on these 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 approximately $1.0 billion at March 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. The remaining weighted average life of all contracts was approximately 2.7 years at March 31, 2018. 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 March 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. Derivative contract assets included in other assets were $141 million as of March 31, 2018 and $142 million as of December 31, 2017. Derivative contract liabilities included in other liabilities were $105 million as of March 31, 2018 and $82 million as of December 31, 2017. 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. Unrealized gains or losses on contracts accounted for as cash flow or fair value hedges are recorded in other comprehensive income or in net earnings, as appropriate.

Supplemental cash flow informat

Supplemental cash flow information	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental cash flow information	Note 14. Supplemental cash flow information Supplemental cash flow information follows (in millions). First Quarter 2018 2017 Cash paid during the period for: Income taxes $ 289 $ 26 Interest: Insurance and other businesses 338 306 Railroad, utilities and energy businesses 747 737 Finance and financial products businesses 83 78 Non-cash Liabilities assumed in connection with business acquisitions 4 142

Unpaid losses and loss adjustme

Unpaid losses and loss adjustment expenses	3 Months Ended
	Mar. 31, 2018
Insurance [Abstract]
Unpaid losses and loss adjustment expenses	Note 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 incurred-but-not-reported 2018 2017 Balances – beginning of year: Gross liabilities $ 61,122 $ 53,379 Reinsurance recoverable on unpaid losses (3,201 ) (3,338 ) Net liabilities 57,921 50,041 Incurred losses and loss adjustment expenses: Current accident year events 9,475 8,165 Prior accident years’ events (753 ) 134 Total incurred losses and loss adjustment expenses 8,722 8,299 Paid losses and loss adjustment expenses: Current accident year events (3,091 ) (2,678 ) Prior accident years’ events (4,759 ) (4,216 ) Total payments (7,850 ) (6,894 ) Foreign currency translation adjustment 253 77 Balances – March 31: Net liabilities 59,046 51,523 Reinsurance recoverable on unpaid losses 3,048 3,221 Gross liabilities $ 62,094 $ 54,744 Incurred losses and loss adjustment expenses in the first quarter of 2018 included net reductions of estimated ultimate liabilities for prior accident years of $753 million compared to net increases of $134 million in 2017. We decreased estimated ultimate liabilities with respect to primary insurance by $571 million in the first quarter of 2018 and $261 million in 2017. In each period, these reductions primarily related to medical malpractice, workers’ compensation and private passenger automobile insurance. Estimated ultimate liabilities with respect to property and casualty reinsurance decreased by $182 million in the first quarter of 2018 compared to an increase of $395 million in 2017. Incurred losses for prior years’ events in 2017 included increases in the estimated liabilities for certain personal injury claims in the United Kingdom due to a regulatory decision, for unanticipated property claims under certain reinsurance contracts and for estimates of IBNR losses.

Retroactive reinsurance contrac

Retroactive reinsurance contracts	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Retroactive reinsurance contracts	Note 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 months ending March 31, 2018 and 2017 follows (in millions). 2018 2017 Unpaid losses Deferred Unpaid losses Deferred Balances – beginning of year: $ 42,937 $ (15,278) $ 24,972 $ (8,047) Incurred losses and loss adjustment expenses Current year contracts — — 16,448 (6,192) Prior years’ contracts (30) 271 (398) 409 Total (30) 271 16,050 (5,783) Paid losses and loss adjustment expenses (563) — (435) — Balances – March 31: $ 42,344 $ (15,007) $ 40,587 $ (13,830) Incurred losses and loss adjustment expenses, net of deferred charges $ 241 $ 10,267 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 the first quarter of 2017, we entered into an agreement through a Berkshire subsidiary, National Indemnity Company (“NICO”), 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, 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. Our estimated ultimate claim liabilities with respect to the AIG contract at March 31, 2018 and at December 31, 2017 were $18.2 billion. Deferred charge assets were approximately $7.4 billion at March 31, 2018 and $7.5 billion at December 31, 2017, which reflected an increase in estimated ultimate liabilities recorded in the fourth quarter of 2017 of $1.8 billion. Incurred losses and loss adjustment expenses related to contracts written in prior years were $241 million in the first quarter of 2018 and $11 million in the first quarter of 2017. Such losses included recurring amortization of deferred charge assets and net gains from contract commutations in 2018 and 2017.

Notes payable and other borrowi

Notes payable and other borrowings	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Notes payable and other borrowings	Note 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 March 31, 2018. Weighted March 31, 2018 December 31, Insurance and other: Issued by Berkshire: U.S. Dollar denominated borrowings due 2018-2047 3.0% $ 9,804 $10,603 Euro denominated borrowings due 2020-2035 1.1% 8,383 8,164 Short-term subsidiary borrowings 3.7% 1,800 1,832 Other subsidiary borrowings due 2018-2045 4.0% 5,676 6,725 $ 25,663 $27,324 In 2018, the carrying value of Berkshire’s Euro denominated senior notes increased $217 million due to changes in the Euro/U.S. Dollar exchange rates. This increase produced a corresponding charge to pre-tax non-cash Weighted March 31, December 31, Railroad, utilities and energy: Issued by Berkshire Hathaway Energy Company (“BHE”) and its subsidiaries: BHE senior unsecured debt due 2018-2048 4.6% $ 8,627 $ 6,452 Subsidiary and other debt due 2018-2064 4.8% 28,871 28,739 Short-term debt 2.6% 2,608 4,488 Issued by BNSF due 2018-2097 4.7% 22,561 22,499 $ 62,667 $ 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, but not limited to, leverage ratios, interest coverage ratios and debt service coverage ratios, among other covenants. In January 2018, BHE issued $2.2 billion of senior notes with maturity dates ranging from 2021 to 2048 with a weighted average interest rate of 3.2%. Proceeds from this debt issuance were used to repay short-term debt and for general corporate purposes. BNSF’s borrowings are primarily senior unsecured debentures. In the first quarter of 2018, BNSF issued $750 million of 4.05% senior unsecured debentures due in 2048 and $650 million of debentures matured. As of March 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. Weighted March 31, December 31, Finance and financial products: Issued by Berkshire Hathaway Finance Corporation (“BHFC”) due 2018-2043 3.1% $ 10,578 $ 12,926 Issued by other subsidiaries due 2019-2028 4.0% 177 159 $ 10,755 $ 13,085 Borrowings of BHFC are used to fund manufactured housing loans originated or acquired and assets held for lease of certain finance subsidiaries. The borrowings of BHFC, a wholly owned finance subsidiary of Berkshire, consist of senior unsecured notes, which are fully and unconditionally guaranteed by Berkshire. During the first quarter of 2018, $2.35 billion of BHFC senior notes matured. As of March 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 about $5.3 billion related to BHE and its subsidiaries. In addition to BHFC’s borrowings, at March 31, 2018, Berkshire guaranteed approximately $1.9 billion of other subsidiary borrowings. 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.

Fair value measurements

Fair value measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	Note 18. Fair value measurements Our financial assets and liabilities are summarized below as of March 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 March 31, 2018 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 3,608 $ 3,608 $ 2,399 $ 1,209 $ — States, municipalities and political subdivisions 759 759 — 759 — Foreign governments 7,888 7,888 5,906 1,982 — Corporate bonds 6,819 6,819 — 6,813 6 Mortgage-backed securities 846 846 — 846 — Investments in equity securities 172,976 172,976 172,928 48 — Investment in Kraft Heinz common stock 17,687 20,272 20,272 — — Loans and finance receivables 13,845 14,084 — 18 14,066 Derivative contract assets (1) 141 141 1 26 114 Derivative contract liabilities: Railroad, utilities and energy (1) 105 105 — 88 17 Equity index put options 2,378 2,378 — — 2,378 Notes payable and other borrowings: Insurance and other 25,663 26,046 — 26,046 — Railroad, utilities and energy 62,667 68,603 — 68,603 — Finance and financial products 10,755 11,059 — 11,035 24 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 27,324 28,180 — 28,180 — Railroad, utilities and energy 62,178 70,538 — 70,538 — Finance and financial products 13,085 13,582 — 13,577 5 (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 the three months ended March 31, 2018 and 2017 follow (in millions). Investments Net Three months ending March 31, 2018 Balance at December 31, 2017 $ 6 $ (2,069 ) Gains (losses) included in: Earnings — (176 ) Other comprehensive income — (1 ) Regulatory assets and liabilities — (9 ) Acquisitions, dispositions and settlements — (26 ) Transfers into/out of Level 3 — — Balance at March 31, 2018 $ 6 $ (2,281 ) Three months ending March 31, 2017 Balance at December 31, 2016 $ 17,321 $ (2,824 ) Gains (losses) included in: Earnings — 499 Other comprehensive income 1,157 (2 ) Regulatory assets and liabilities — 1 Acquisitions, dispositions and settlements (3 ) (23 ) Transfers into/out of Level 3 (1 ) — Balance at March 31, 2017 $ 18,474 $ (2,349 ) Gains and losses included in earnings are included as components of investment gains/losses, derivative gains/losses and other revenues, as appropriate. Gains and losses included in other comprehensive income are primarily the net change in unrealized appreciation of investments and the reclassification of investment appreciation in net earnings, as appropriate in our Consolidated Statements of Comprehensive Income. Quantitative information as of March 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 liabilities: Equity index put options $2,378 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. 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	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Common stock	Note 19. Common stock Changes in Berkshire’s issued, treasury and outstanding common stock during the three months ending March 31, 2018 are shown in the table below. Class A, $5 Par Value Class B, $0.0033 Par Value Issued Treasury Outstanding Issued Treasury Outstanding Balance at 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 (3,038 ) — (3,038 ) 4,806,083 — 4,806,083 Balance at March 31, 2018 759,717 (11,680 ) 748,037 1,346,872,832 (1,409,762 ) 1,345,463,070 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 Berkshire’s Board of Directors has approved a common stock repurchase program permitting 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. The program allows 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	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated other comprehensive income	Note 20. Accumulated other comprehensive income A summary of the net changes in after-tax Unrealized Foreign Prior service Other Accumulated 2018 Balance at December 31, 2017 $ 62,093 $ (3,114 ) $ (420 ) $ 12 $ 58,571 Reclassifications to retained earnings (61,340 ) (65 ) 36 (6 ) (61,375 ) Other comprehensive income, net before reclassifications (74 ) 585 (17 ) 2 496 Reclassifications into net earnings (175 ) — 9 (3 ) (169 ) Balance at March 31, 2018 $ 504 $ (2,594 ) $ (392 ) $ 5 $ (2,477 ) Reclassifications into net earnings: Reclassifications before income taxes $ (221 ) $ — $ 10 $ (5 ) $ (216 ) Applicable income taxes (46 ) — 1 (2 ) (47 ) $ (175 ) $ — $ 9 $ (3 ) $ (169 ) 2017 Balance at December 31, 2016 $ 43,176 $ (5,268 ) $ (593 ) $ (17 ) $ 37,298 Other comprehensive income, net before reclassifications 5,497 475 (22 ) (6 ) 5,944 Reclassifications into net earnings (198 ) — 18 8 (172 ) Balance at March 31, 2017 $ 48,475 $ (4,793 ) $ (597 ) $ (15 ) $ 43,070 Reclassifications into net earnings: Reclassifications before income taxes $ (305 ) $ — $ 24 $ 14 $ (267 ) Applicable income taxes (107 ) — 6 6 (95 ) $ (198 ) $ — $ 18 $ 8 $ (172 )

Contingencies and Commitments

Contingencies and Commitments	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	Note 21. 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. In 2016, NICO entered into a definitive agreement to acquire Medical Liability Mutual Insurance Company (“MLMIC”), a writer of medical professional liability insurance domiciled in New York. The acquisition price will be approximately $2.5 billion. The acquisition will involve the conversion of MLMIC from a mutual company to a stock company. The closing of the transaction is subject to various regulatory approvals, customary closing conditions and the approval of the MLMIC policyholders eligible to vote on the proposed demutualization and sale. We currently expect this acquisition will be completed in the third quarter of 2018.

Business segment data

Business segment data	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Business segment data	Note 22. Business segment data Our operating businesses include a large and diverse group of insurance, railroad, utilities and energy, finance, manufacturing, service and retailing businesses. Our reportable business segments are organized in a manner that reflects how management views those business activities. Certain businesses have been 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. Revenues by segment for the first quarter of 2018 and 2017 were as follows (in millions). First Quarter 2018 2017 Operating Businesses: Insurance: Underwriting: GEICO $ 7,915 $ 6,845 Berkshire Hathaway Reinsurance Group 3,540 13,232 Berkshire Hathaway Primary Group 1,918 1,676 Investment income 1,213 1,132 Total insurance 14,586 22,885 BNSF 5,624 5,185 Berkshire Hathaway Energy 4,512 4,231 Manufacturing 12,934 12,097 McLane Company 12,189 12,101 Service and retailing 6,587 6,093 Finance and financial products 2,063 1,849 58,495 64,441 Reconciliation of segments to consolidated amount: Corporate, eliminations and other (22) (71) $ 58,473 $ 64,370 Earnings before income taxes by segment for the first quarter of 2018 and 2017 were as follows (in millions). First Quarter 2018 2017 Operating Businesses: Insurance: Underwriting: GEICO $ 677 $ 175 Berkshire Hathaway Reinsurance Group (258) (743) Berkshire Hathaway Primary Group 99 189 Investment income 1,205 1,129 Total insurance 1,723 750 BNSF 1,513 1,345 Berkshire Hathaway Energy 487 589 Manufacturing 1,855 1,487 McLane Company 60 88 Service and retailing 515 393 Finance and financial products 494 450 6,647 5,102 Reconciliation of segments to consolidated amount: Investment and derivative gains/losses (8,015) 775 Interest expense, not allocated to segments (337) (211) Equity method investments 401 281 Corporate, eliminations and other (219) (259) $ (1,523) $ 5,688

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	On January 1, 2018, we adopted Accounting Standards Update (“ASU”) 2016-01 2016-01”), 2018-02 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 ) (71 ) 61,304 Shareholders’ equity $ — $ — $ (71 ) $ (71 ) With respect to ASU 2016-01, after-tax 2016-01 available-for-sale We also reclassified the stranded deferred income taxes in accumulated other comprehensive income as of January 1, 2018 to retained earnings in connection with our adoption of ASU 2018-02. We adopted ASC 606 using the modified retrospective method, whereby the cumulative effect of the adoption was recorded as an adjustment to retained earnings. Prior year financial statements were not restated. The initial adoption of ASC 606 resulted in an increase to both assets (primarily property, plant and equipment) and liabilities and a relatively minor reduction in retained earnings as of the beginning of 2018. ASC 606 also provides for certain other disclosures which are included in Note 3. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02 2016-02 right-of-use 2016-02 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

New Accounting Pronouncements32

New Accounting Pronouncements (Tables)	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [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 ) (71 ) 61,304 Shareholders’ equity — — (71 ) (71 )

Revenues from contracts with 33

Revenues from contracts with customers (Tables)	3 Months Ended
	Mar. 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 three months ended March 31, 2018 (in millions). Other revenues included in our consolidated revenues were primarily insurance premiums earned, interest, dividend and other investment income and lease income which are not within the scope of ASC 606. Manufacturing McLane Service and BNSF Berkshire Finance and Insurance, Total Manufactured products: Industrial and commercial products $ 6,393 $ — $ 54 $ — $ — $ 161 $ — $ 6,608 Building products 2,919 — — — — 1 — 2,920 Consumer products 2,848 — — — — 848 — 3,696 Grocery and convenience store distribution — 8,512 — — — — — 8,512 Food and beverage distribution — 3,643 — — — — — 3,643 Auto sales — — 1,931 — — — — 1,931 Other retail and wholesale distribution 496 — 2,694 — — 20 — 3,210 Service 218 17 942 5,580 700 8 — 7,465 Electricity and natural gas — — — — 3,524 — — 3,524 Total 12,874 12,172 5,621 5,580 4,224 1,038 — 41,509 Other revenue 38 17 939 10 288 1,022 14,650 16,964 $ 12,912 $ 12,189 $ 6,560 $ 5,590 $ 4,512 $ 2,060 $ 14,650 $ 58,473
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 March 31, 2018 follows (in millions). Such contracts relate to our utilities and energy businesses. Performance obligations Less than Greater than Total Electricity and natural gas $ 1,007 $ 4,352 $ 5,359

Investments in fixed maturity34

Investments in fixed maturity securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in securities with fixed maturities	Investments in securities with fixed maturities as of March 31, 2018 and December 31, 2017 are summarized by type below (in millions). Amortized Unrealized Unrealized Fair March 31, 2018 U.S. Treasury, U.S. government corporations and agencies $ 3,633 $ 11 $ (36 ) $ 3,608 States, municipalities and political subdivisions 737 30 (8 ) 759 Foreign governments 7,837 83 (32 ) 7,888 Corporate bonds 6,308 519 (8 ) 6,819 Mortgage-backed securities 761 88 (3 ) 846 $ 19,276 $ 731 $ (87 ) $ 19,920 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 securities with fixed maturities at March 31, 2018 are summarized below by contractual maturity dates. Actual maturities may differ from contractual maturities due to early call or prepayment rights held by issuers. Amounts are in millions. Due in one Due after one Due after five Due after Mortgage- Total Amortized cost $ 7,178 $ 9,884 $ 460 $ 993 $ 761 $ 19,276 Fair value 7,227 9,982 515 1,350 846 19,920

Investments in equity securit35

Investments in equity securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in equity securities	Investments in equity securities as of March 31, 2018 and December 31, 2017 are summarized based on the primary industry of the investee in the table below (in millions). Cost Basis Net Unrealized Gains Fair Value March 31, 2018 Banks, insurance and finance $ 25,986 $ 50,091 $ 76,077 Consumer products 38,130 23,864 61,994 Commercial, industrial and other 21,714 13,191 34,905 $ 85,830 $ 87,146 $ 172,976 * Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company – $14.1 billion; Apple Inc. – $40.7 billion; Bank of America Corporation – $21.0 billion; The Coca-Cola Company – $17.4 billion and Wells Fargo & Company – $25.2 billion). Cost Basis Net Unrealized Gains Fair Value 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). Investments in equity securities are reflected in our Consolidated Balance Sheets as follows (in millions). March 31, 2018 December 31, 2017 Insurance and other $ 166,658 $ 164,026 Railroad, utilities and energy * 1,755 1,961 Finance and financial products * 4,563 4,553 $ 172,976 $ 170,540 * Included in other assets.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Summarized consolidated financial information of Kraft Heinz	Summarized consolidated financial information of Kraft Heinz follows (in millions). March 31, 2018 December 30, 2017 Assets $ 120,787 $120,232 Liabilities 54,324 53,985 First Quarter 2018 2017 Sales $ 6,304 $ 6,324 Net earnings attributable to Kraft Heinz common shareholders $ 993 $ 893

Investment gains_losses (Tables

Investment gains/losses (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of investment gains and losses	A summary of investment gains and losses in the first quarter of 2018 and 2017 follows (in millions). 2018 2017 Equity securities: Investment gains and losses during 2018 on securities sold in 2018 $ (240) $ — Unrealized investment gains and losses on securities held at the end of the period (7,807) — Gross realized gains — 425 Gross realized losses — (125 ) (8,047) 300 Fixed maturity securities: Gross realized gains 359 11 Gross realized losses (138) (6 ) Other 17 10 $(7,809) $ 315

Receivables (Tables)

Receivables (Tables)	3 Months Ended
	Mar. 31, 2018
Insurance and Other [Member]
Schedule of receivables	Receivables of insurance and other businesses are comprised of the following (in millions). March 31, 2018 December 31, 2017 Insurance premiums receivable $ 12,570 $ 11,058 Reinsurance recoverable on unpaid losses 3,048 3,201 Trade receivables 12,568 11,756 Other 3,078 2,925 Allowances for uncollectible accounts (358) (362) $ 30,906 $ 28,578
Finance and Financial Products [Member]
Schedule of receivables	A summary of loans and finance receivables of our finance and financial products businesses follows (in millions). March 31, December 31, 2017 Loans and finance receivables before allowances and discounts $ 14,209 $ 14,126 Allowances for uncollectible loans (179) (180) Unamortized acquisition discounts (185) (198) $ 13,845 $ 13,748

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories are comprised of the following (in millions). March 31, 2018 December 31, 2017 Raw materials $ 3,094 $ 2,997 Work in process and other 2,228 2,315 Finished manufactured goods 4,188 4,179 Goods acquired for resale 6,734 6,696 $ 16,244 $ 16,187

Property, plant and equipment40

Property, plant and equipment and assets held for lease (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of depreciation expense	A summary of depreciation expense for the first quarters of 2018 and 2017 follows (in millions). First Quarter 2018 2017 Insurance and other $ 649 $ 542 Railroad, utilities and energy 1,225 1,175 Finance and financial products 161 159 $ 2,035 $ 1,876
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). In conjunction with the adoption of ASC 606, we recorded a net asset of approximately $3.5 billion in aircraft sold under fractional aircraft ownership programs in machinery and equipment. Such amount consisted of cost of approximately $5.3 billion and accumulated depreciation of $1.8 billion. We also recorded other liabilities of approximately $3.5 billion for estimated repurchase obligations and unearned lease revenues, substantially offsetting the amount recorded in machinery and equipment. See Note 2. March 31, 2018 December 31, 2017 Land $ 2,310 $ 2,292 Buildings and improvements 8,961 8,810 Machinery and equipment 27,707 21,935 Furniture, fixtures and other 4,493 4,387 43,471 37,424 Accumulated depreciation (19,664 ) (17,320 ) $ 23,807 $20,104
Finance and Financial Products [Member]
Schedule of property, plant and equipment	Assets held for lease and property, plant and equipment of our finance and financial products businesses are summarized below (in millions). Assets held for lease includes railcars, intermodal tank containers, cranes, over-the-road March 31, 2018 December 31, 2017 Assets held for lease $ 12,337 $ 12,318 Land 232 231 Buildings, machinery and other 1,464 1,444 14,033 13,993 Accumulated depreciation (4,113 ) (4,062 ) $ 9,920 $ 9,931
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. March 31, 2018 December 31, 2017 Railroad: Land $ 6,090 $ 6,088 Track structure and other roadway 51,652 51,320 Locomotives, freight cars and other equipment 12,600 12,543 Construction in progress 943 989 71,285 70,940 Accumulated depreciation (8,954 ) (8,627 ) 62,331 62,313 Utilities and energy: Utility generation, transmission and distribution systems 75,068 74,660 Interstate natural gas pipeline assets 7,230 7,176 Independent power plants and other assets 7,622 7,499 Construction in progress 2,735 2,556 92,655 91,891 Accumulated depreciation (26,601 ) (26,020 ) 66,054 65,871 $ 128,385 $ 128,184

Goodwill and other intangible41

Goodwill and other intangible assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Reconciliation of the change in goodwill	A reconciliation of the change in the carrying value of goodwill is as follows (in millions). March 31, December 31, Balance at beginning of year $ 81,258 $ 79,486 Acquisitions of businesses 52 1,545 Other, including foreign currency translation 27 227 Balance at end of period $ 81,337 $ 81,258
Schedule of intangible assets	Other intangible assets are summarized as follows (in millions). March 31, 2018 December 31, 2017 Gross carrying amount Accumulated Gross carrying Accumulated Insurance and other $ 40,317 $ 8,057 $ 40,225 $ 7,707 Railroad, utilities and energy 993 334 988 324 $ 41,310 $ 8,391 $ 41,213 $ 8,031 Trademarks and trade names $ 5,394 $ 710 $ 5,381 $ 692 Patents and technology 4,383 2,579 4,341 2,493 Customer relationships 28,353 3,943 28,322 3,722 Other 3,180 1,159 3,169 1,124 $ 41,310 $ 8,391 $ 41,213 $ 8,031

Derivative contracts (Tables)

Derivative contracts (Tables) - Finance and Financial Products [Member]	3 Months Ended
	Mar. 31, 2018
Derivative contracts outstanding	The liabilities and related notional values of such contracts follows (in millions). March 31, 2018 December 31, 2017 Liabilities Notional Value Liabilities Notional Value Equity index put options $ 2,378 $ 29,479 (1) $ 2,172 $ 28,753 (1) (1) 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.
Derivative gains/losses included in the Consolidated Statements of Earnings	A summary of derivative contract gains/losses included in our Consolidated Statements of Earnings in the first quarter of 2018 and 2017 follows (in millions). First Quarter 2018 2017 Equity index put options $ (206 ) $ 460

Supplemental cash flow inform43

Supplemental cash flow information (Tables)	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Schedule of supplemental cash flow information	Supplemental cash flow information follows (in millions). First Quarter 2018 2017 Cash paid during the period for: Income taxes $ 289 $ 26 Interest: Insurance and other businesses 338 306 Railroad, utilities and energy businesses 747 737 Finance and financial products businesses 83 78 Non-cash Liabilities assumed in connection with business acquisitions 4 142

Unpaid losses and loss adjust44

Unpaid losses and loss adjustment expenses (Tables)	3 Months Ended
	Mar. 31, 2018
Insurance [Abstract]
Schedule of liability for unpaid claims and claims adjustment expense	Reconciliations of the changes in claim liabilities, excluding liabilities under retroactive reinsurance contracts (see Note 16), for each of the three months ending March 31, 2018 and 2017 follow (in millions). 2018 2017 Balances – beginning of year: Gross liabilities $ 61,122 $ 53,379 Reinsurance recoverable on unpaid losses (3,201 ) (3,338 ) Net liabilities 57,921 50,041 Incurred losses and loss adjustment expenses: Current accident year events 9,475 8,165 Prior accident years’ events (753 ) 134 Total incurred losses and loss adjustment expenses 8,722 8,299 Paid losses and loss adjustment expenses: Current accident year events (3,091 ) (2,678 ) Prior accident years’ events (4,759 ) (4,216 ) Total payments (7,850 ) (6,894 ) Foreign currency translation adjustment 253 77 Balances – March 31: Net liabilities 59,046 51,523 Reinsurance recoverable on unpaid losses 3,048 3,221 Gross liabilities $ 62,094 $ 54,744

Retroactive reinsurance contr45

Retroactive reinsurance contracts (Tables)	3 Months Ended
	Mar. 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 months ending March 31, 2018 and 2017 follows (in millions). 2018 2017 Unpaid losses Deferred Unpaid losses Deferred Balances – beginning of year: $ 42,937 $ (15,278) $ 24,972 $ (8,047) Incurred losses and loss adjustment expenses Current year contracts — — 16,448 (6,192) Prior years’ contracts (30) 271 (398) 409 Total (30) 271 16,050 (5,783) Paid losses and loss adjustment expenses (563) — (435) — Balances – March 31: $ 42,344 $ (15,007) $ 40,587 $ (13,830) Incurred losses and loss adjustment expenses, net of deferred charges $ 241 $ 10,267

Notes payable and other borro46

Notes payable and other borrowings (Tables)	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018. Weighted March 31, 2018 December 31, Insurance and other: Issued by Berkshire: U.S. Dollar denominated borrowings due 2018-2047 3.0% $ 9,804 $10,603 Euro denominated borrowings due 2020-2035 1.1% 8,383 8,164 Short-term subsidiary borrowings 3.7% 1,800 1,832 Other subsidiary borrowings due 2018-2045 4.0% 5,676 6,725 $ 25,663 $27,324
Finance and Financial Products [Member]
Schedule of short and long term outstanding debt disclosure	Weighted March 31, December 31, Finance and financial products: Issued by Berkshire Hathaway Finance Corporation (“BHFC”) due 2018-2043 3.1% $ 10,578 $ 12,926 Issued by other subsidiaries due 2019-2028 4.0% 177 159 $ 10,755 $ 13,085
Railroad, Utilities and Energy [Member]
Schedule of short and long term outstanding debt disclosure	Weighted March 31, December 31, Railroad, utilities and energy: Issued by Berkshire Hathaway Energy Company (“BHE”) and its subsidiaries: BHE senior unsecured debt due 2018-2048 4.6% $ 8,627 $ 6,452 Subsidiary and other debt due 2018-2064 4.8% 28,871 28,739 Short-term debt 2.6% 2,608 4,488 Issued by BNSF due 2018-2097 4.7% 22,561 22,499 $ 62,667 $ 62,178

Fair value measurements (Tables

Fair value measurements (Tables)	3 Months Ended
	Mar. 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 March 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 March 31, 2018 Investments in fixed maturity securities: U.S. Treasury, U.S. government corporations and agencies $ 3,608 $ 3,608 $ 2,399 $ 1,209 $ — States, municipalities and political subdivisions 759 759 — 759 — Foreign governments 7,888 7,888 5,906 1,982 — Corporate bonds 6,819 6,819 — 6,813 6 Mortgage-backed securities 846 846 — 846 — Investments in equity securities 172,976 172,976 172,928 48 — Investment in Kraft Heinz common stock 17,687 20,272 20,272 — — Loans and finance receivables 13,845 14,084 — 18 14,066 Derivative contract assets (1) 141 141 1 26 114 Derivative contract liabilities: Railroad, utilities and energy (1) 105 105 — 88 17 Equity index put options 2,378 2,378 — — 2,378 Notes payable and other borrowings: Insurance and other 25,663 26,046 — 26,046 — Railroad, utilities and energy 62,667 68,603 — 68,603 — Finance and financial products 10,755 11,059 — 11,035 24 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 27,324 28,180 — 28,180 — Railroad, utilities and energy 62,178 70,538 — 70,538 — Finance and financial products 13,085 13,582 — 13,577 5 (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 the three months ended March 31, 2018 and 2017 follow (in millions). Investments Net Three months ending March 31, 2018 Balance at December 31, 2017 $ 6 $ (2,069 ) Gains (losses) included in: Earnings — (176 ) Other comprehensive income — (1 ) Regulatory assets and liabilities — (9 ) Acquisitions, dispositions and settlements — (26 ) Transfers into/out of Level 3 — — Balance at March 31, 2018 $ 6 $ (2,281 ) Three months ending March 31, 2017 Balance at December 31, 2016 $ 17,321 $ (2,824 ) Gains (losses) included in: Earnings — 499 Other comprehensive income 1,157 (2 ) Regulatory assets and liabilities — 1 Acquisitions, dispositions and settlements (3 ) (23 ) Transfers into/out of Level 3 (1 ) — Balance at March 31, 2017 $ 18,474 $ (2,349 )
Fair value assets and liabilities measured on recurring basis, unobservable inputs, additional information	Quantitative information as of March 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 liabilities: Equity index put options $2,378 Option pricing model Volatility 18%

Common stock (Tables)

Common stock (Tables)	3 Months Ended
	Mar. 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 months ending March 31, 2018 are shown in the table below. Class A, $5 Par Value Class B, $0.0033 Par Value Issued Treasury Outstanding Issued Treasury Outstanding Balance at 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 (3,038 ) — (3,038 ) 4,806,083 — 4,806,083 Balance at March 31, 2018 759,717 (11,680 ) 748,037 1,346,872,832 (1,409,762 ) 1,345,463,070

Accumulated other comprehensi49

Accumulated other comprehensive income (Tables)	3 Months Ended
	Mar. 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 2018 Balance at December 31, 2017 $ 62,093 $ (3,114 ) $ (420 ) $ 12 $ 58,571 Reclassifications to retained earnings (61,340 ) (65 ) 36 (6 ) (61,375 ) Other comprehensive income, net before reclassifications (74 ) 585 (17 ) 2 496 Reclassifications into net earnings (175 ) — 9 (3 ) (169 ) Balance at March 31, 2018 $ 504 $ (2,594 ) $ (392 ) $ 5 $ (2,477 ) Reclassifications into net earnings: Reclassifications before income taxes $ (221 ) $ — $ 10 $ (5 ) $ (216 ) Applicable income taxes (46 ) — 1 (2 ) (47 ) $ (175 ) $ — $ 9 $ (3 ) $ (169 ) 2017 Balance at December 31, 2016 $ 43,176 $ (5,268 ) $ (593 ) $ (17 ) $ 37,298 Other comprehensive income, net before reclassifications 5,497 475 (22 ) (6 ) 5,944 Reclassifications into net earnings (198 ) — 18 8 (172 ) Balance at March 31, 2017 $ 48,475 $ (4,793 ) $ (597 ) $ (15 ) $ 43,070 Reclassifications into net earnings: Reclassifications before income taxes $ (305 ) $ — $ 24 $ 14 $ (267 ) Applicable income taxes (107 ) — 6 6 (95 ) $ (198 ) $ — $ 18 $ 8 $ (172 )

Business segment data (Tables)

Business segment data (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of revenues and earnings by segment	Revenues by segment for the first quarter of 2018 and 2017 were as follows (in millions). First Quarter 2018 2017 Operating Businesses: Insurance: Underwriting: GEICO $ 7,915 $ 6,845 Berkshire Hathaway Reinsurance Group 3,540 13,232 Berkshire Hathaway Primary Group 1,918 1,676 Investment income 1,213 1,132 Total insurance 14,586 22,885 BNSF 5,624 5,185 Berkshire Hathaway Energy 4,512 4,231 Manufacturing 12,934 12,097 McLane Company 12,189 12,101 Service and retailing 6,587 6,093 Finance and financial products 2,063 1,849 58,495 64,441 Reconciliation of segments to consolidated amount: Corporate, eliminations and other (22) (71) $ 58,473 $ 64,370 Earnings before income taxes by segment for the first quarter of 2018 and 2017 were as follows (in millions). First Quarter 2018 2017 Operating Businesses: Insurance: Underwriting: GEICO $ 677 $ 175 Berkshire Hathaway Reinsurance Group (258) (743) Berkshire Hathaway Primary Group 99 189 Investment income 1,205 1,129 Total insurance 1,723 750 BNSF 1,513 1,345 Berkshire Hathaway Energy 487 589 Manufacturing 1,855 1,487 McLane Company 60 88 Service and retailing 515 393 Finance and financial products 494 450 6,647 5,102 Reconciliation of segments to consolidated amount: Investment and derivative gains/losses (8,015) 775 Interest expense, not allocated to segments (337) (211) Equity method investments 401 281 Corporate, eliminations and other (219) (259) $ (1,523) $ 5,688

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	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets	$ 702,651		$ 702,095
Liabilities	351,599		350,141
Accumulated other comprehensive income	(2,477)		58,571
Retained earnings	315,952		255,786
Shareholders' equity	$ 351,052		$ 351,954	$ 295,349	$ 285,428
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		(71)
Shareholders' equity		(71)
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		61,304
Shareholders' equity		$ (71)

Revenues from contracts with 52

Revenues from contracts with customers - Narrative (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Assets	$ 702,651		$ 702,095
Liabilities	351,599		350,141
ASC 606 [Member]
Disaggregation of Revenue [Line Items]
Assets		$ 3,382
Liabilities		3,453
Utilities and Energy [Member] | Other Assets [Member]
Disaggregation of Revenue [Line Items]
Unbilled revenue	$ 582		$ 665
Sales of Fractional Aircraft Ownership Interests [Member] | ASC 606 [Member]
Disaggregation of Revenue [Line Items]
Liabilities		3,500
Sales of Fractional Aircraft Ownership Interests [Member] | ASC 606 [Member] | Primarily Property, Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Assets		$ 3,500

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
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 41,509
Other revenue	16,964
Total revenues	58,473	$ 64,370
Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,608
Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,920
Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,696
Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,512
Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,643
Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,931
Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,210
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,465
Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,524
Manufacturing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,874
Other revenue	38
Total revenues	12,912
Manufacturing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,393
Manufacturing Businesses [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,919
Manufacturing Businesses [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,848
Manufacturing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	496
Manufacturing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	218
McLane Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,172
Other revenue	17
Total revenues	12,189
McLane Company [Member] | Grocery and Convenience Store Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,512
McLane Company [Member] | Food and Beverage Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,643
McLane Company [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	17
Service and Retailing Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,621
Other revenue	939
Total revenues	6,560
Service and Retailing Businesses [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	54
Service and Retailing Businesses [Member] | Auto Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,931
Service and Retailing Businesses [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,694
Service and Retailing Businesses [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	942
BNSF [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,580
Other revenue	10
Total revenues	5,590
BNSF [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,580
Berkshire Hathaway Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,224
Other revenue	288
Total revenues	4,512
Berkshire Hathaway Energy [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	700
Berkshire Hathaway Energy [Member] | Electricity and Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,524
Finance and Financial Products Reportable Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,038
Other revenue	1,022
Total revenues	2,060
Finance and Financial Products Reportable Segment [Member] | Industrial and Commercial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	161
Finance and Financial Products Reportable Segment [Member] | Building Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1
Finance and Financial Products Reportable Segment [Member] | Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	848
Finance and Financial Products Reportable Segment [Member] | Other Retail and Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	20
Finance and Financial Products Reportable Segment [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8
Insurance Corporate And Other [Member]
Disaggregation of Revenue [Line Items]
Other revenue	14,650
Total revenues	$ 14,650

Revenue from contracts with c54

Revenue from contracts with customers transaction price allocated to remaining performance obligations (Detail) - Electricity and Natural Gas [Member] $ in Millions	Mar. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 5,359
Less than 12 Months [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 1,007
Performance obligations expected to be satisfied, period	1 year
Greater than 12 Months [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 4,352
Performance obligations expected to be satisfied, period

Investments in fixed maturity55

Investments in fixed maturity securities (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	$ 19,276	$ 20,445
Unrealized gains on fixed maturity securities	731	977
Unrealized losses on fixed maturity securities	(87)	(69)
Fair value of fixed maturity securities	19,920	21,353
U.S. Treasury, U.S. government corporations and agencies [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	3,633	3,975
Unrealized gains on fixed maturity securities	11	4
Unrealized losses on fixed maturity securities	(36)	(26)
Fair value of fixed maturity securities	3,608	3,953
States, municipalities and political subdivisions [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	737	847
Unrealized gains on fixed maturity securities	30	19
Unrealized losses on fixed maturity securities	(8)	(12)
Fair value of fixed maturity securities	759	854
Foreign governments [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	7,837	8,572
Unrealized gains on fixed maturity securities	83	274
Unrealized losses on fixed maturity securities	(32)	(24)
Fair value of fixed maturity securities	7,888	8,822
Corporate bonds [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	6,308	6,279
Unrealized gains on fixed maturity securities	519	588
Unrealized losses on fixed maturity securities	(8)	(5)
Fair value of fixed maturity securities	6,819	6,862
Mortgage-backed securities [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of fixed maturity securities	761	772
Unrealized gains on fixed maturity securities	88	92
Unrealized losses on fixed maturity securities	(3)	(2)
Fair value of fixed maturity securities	$ 846	$ 862

Investments in fixed maturity56

Investments in fixed maturity securities - Narrative (Detail)	Mar. 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	89.00%

Investments in fixed maturity57

Investments in fixed maturity securities - Amortized cost and estimated fair value of securities with fixed maturities (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Due in one year or less - amortized cost	$ 7,178
Due after one year through five years - amortized cost	9,884
Due after five years through ten years - amortized cost	460
Due after ten years - amortized cost	993
Amortized cost of fixed maturity securities	19,276	$ 20,445
Due in one year or less - fair value	7,227
Due after one year through five years - fair value	9,982
Due after five years through ten years - fair value	515
Due after ten years - fair value	1,350
Fair value of fixed maturity securities	19,920	21,353
Mortgage-backed securities [Member]
Summary of Investment Holdings [Line Items]
Amortized cost of mortgage-backed securities	761
Amortized cost of fixed maturity securities	761	772
Fair value of mortgage-backed securities	846
Fair value of fixed maturity securities	$ 846	$ 862

Investments in equity securit58

Investments in equity securities (Detail) - USD ($) $ in Millions	Mar. 31, 2018		Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Cost basis of investments	$ 85,830		$ 74,676
Net Unrealized Holding Gains on investments	87,146		95,864
Fair value of investments	172,976	[1]	170,540	[2]
Banks, insurance and finance [Member]
Summary of Investment Holdings [Line Items]
Cost basis of investments	25,986		25,783
Net Unrealized Holding Gains on investments	50,091		55,026
Fair value of investments	76,077		80,809
Consumer products [Member]
Summary of Investment Holdings [Line Items]
Cost basis of investments	38,130		25,177
Net Unrealized Holding Gains on investments	23,864		25,698
Fair value of investments	61,994		50,875
Commercial, industrial and other [Member]
Summary of Investment Holdings [Line Items]
Cost basis of investments	21,714		23,716
Net Unrealized Holding Gains on investments	13,191		15,140
Fair value of investments	$ 34,905		$ 38,856
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.1 billion; Apple Inc. - $40.7 billion; Bank of America Corporation - $21.0 billion; The Coca-Cola Company - $17.4 billion and Wells Fargo & Company - $25.2 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 securit59

Investments in equity securities (Parenthetical) (Detail) $ in Millions	Mar. 31, 2018USD ($)Company		Dec. 31, 2017USD ($)Company
Summary of Investment Holdings [Line Items]
Fair value of investments	$ 172,976	[1]	$ 170,540	[2]
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
American Express Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	$ 14,100		$ 15,100
Apple Inc. [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	40,700		28,200
Bank of America Corporation [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	21,000		20,700
The Coca-Cola Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	17,400		18,400
Wells Fargo & Company [Member]
Summary of Investment Holdings [Line Items]
Fair value of investments	$ 25,200		$ 29,300
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.1 billion; Apple Inc. - $40.7 billion; Bank of America Corporation - $21.0 billion; The Coca-Cola Company - $17.4 billion and Wells Fargo & Company - $25.2 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 securit60

Investments in equity securities - Fair value by segment (Detail) - USD ($) $ in Millions		Mar. 31, 2018		Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Investments in equity securities		$ 172,976	[1]	$ 170,540	[2]
Insurance and Other [Member]
Summary of Investment Holdings [Line Items]
Investments in equity securities		166,658		164,026
Railroad, Utilities and Energy [Member] | Other Assets [Member]
Summary of Investment Holdings [Line Items]
Investments in equity securities	[3]	1,755		1,961
Finance and Financial Products [Member] | Other Assets [Member]
Summary of Investment Holdings [Line Items]
Investments in equity securities	[3]	$ 4,563		$ 4,553
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.1 billion; Apple Inc. - $40.7 billion; Bank of America Corporation - $21.0 billion; The Coca-Cola Company - $17.4 billion and Wells Fargo & Company - $25.2 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]	Included in other assets.

Equity Method Investments - Nar

Equity Method Investments - Narrative (Detail) $ in Millions	Oct. 03, 2017USD ($)EmployeeLocation	Mar. 31, 2018USD ($)shares	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Equity method earnings		$ 401	$ 281
Berkadia Commercial Mortgage LLC, Pilot Travel Centers LLC, d/b/a Pilot Flying J, and Electric Transmission Texas [Member]
Schedule of Equity Method Investments [Line Items]
Equity method earnings		$ 136	42
Berkadia Commercial Mortgage (investee) [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Other Assets [Member] | Berkadia Commercial Mortgage LLC, Pilot Travel Centers LLC, d/b/a Pilot Flying J, and Electric Transmission Texas [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 3,500		$ 3,400
Berkshire Hathaway Inc. (Parent) [Member] | Kraft Heinz (previously Heinz Holding) [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		$ 17,687		$ 17,635
Equity method earnings		265	239
Common stock dividends received		$ 203	$ 195
Leucadia National Corporation (venture partner) [Member] | Berkadia Commercial Mortgage (investee) [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
American Electric Power [Member] | Electric Transmission Texas [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Commercial Paper [Member] | Berkadia Commercial Mortgage (investee) [Member]
Schedule of Equity Method Investments [Line Items]
Maximum outstanding balance of commercial paper borrowings		$ 1,500
Insurance Group [Member] | Leucadia National Corporation (venture partner) [Member] | Berkadia Commercial Mortgage (investee) [Member]
Schedule of Equity Method Investments [Line Items]
Reimbursement rate from joint venture partner of Company's surety bond claim losses		50.00%
Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member]
Schedule of Equity Method Investments [Line Items]
Number of locations | Location	750
Annual revenues	$ 20,000
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] | 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%
Berkshire Hathaway Energy Company Subsidiary [Member] | Electric Transmission Texas [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership percentage		50.00%
Minimum [Member] | Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member]
Schedule of Equity Method Investments [Line Items]
Number of team members | Employee	27,000
Agreement to Acquire Additional Interest in 2023 [Member] | Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of additional interest to be acquired	41.40%
Agreement to Acquire Additional Interest in 2023 [Member] | Pilot Travel Centers LLC, d/b/a Pilot Flying J [Member] | Haslam Family [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%

Equity Method Investments - Con

Equity Method Investments - Consolidated financial information (Detail) - Kraft Heinz (previously Heinz Holding) [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 30, 2017
Schedule of Equity Method Investments [Line Items]
Assets	$ 120,787		$ 120,232
Liabilities	54,324		$ 53,985
Sales	6,304	$ 6,324
Net earnings attributable to Kraft Heinz common shareholders	$ 993	$ 893

Income taxes - Narrative (Detai

Income taxes - Narrative (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Effective income tax rate	29.70%	27.20%
Statutory U.S. Corporate income tax rate	21.00%		35.00%

Summary of investment gains and

Summary of investment gains and losses (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Gain (Loss) on Investments [Line Items]
Investment gains and losses during 2018 on equity securities sold in 2018	$ (240)
Unrealized investment gains and losses on equity securities held at the end of the period	(7,807)
Investment gains (losses)	(7,809)	$ 315
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Gross realized gains		425
Gross realized losses		(125)
Investment gains (losses)	(8,047)	300
Fixed Maturities [Member]
Gain (Loss) on Investments [Line Items]
Gross realized gains	359	11
Gross realized losses	(138)	(6)
Other [Member]
Gain (Loss) on Investments [Line Items]
Investment gains (losses)	$ 17	$ 10

Receivables (Detail)

Receivables (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reinsurance recoverable on unpaid losses	$ 3,048	$ 3,201	$ 3,221	$ 3,338
Finance and Financial Products [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and finance receivables before allowances and discounts	14,209	14,126
Allowances for uncollectible loans	(179)	(180)
Unamortized acquisition discounts	(185)	(198)
Total loans and finance receivables of finance and financial products businesses	13,845	13,748
Insurance and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Insurance premiums receivable	12,570	11,058
Reinsurance recoverable on unpaid losses	3,048	3,201
Trade receivables	12,568	11,756
Other	3,078	2,925
Allowances for uncollectible accounts	(358)	(362)
Total receivables of insurance and other businesses	$ 30,906	$ 28,578

Receivables - Narrative (Detail

Receivables - Narrative (Detail) - Finance and Financial Products [Member]	1 Months Ended	3 Months Ended
	Jun. 30, 2017USD ($)	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2018CAD ($)	Jun. 30, 2017CAD ($)
Loans and finance receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provisions for loan losses		$ 34,000,000	$ 38,000,000
Loan charge-offs, net of recoveries		$ 35,000,000	$ 43,000,000
Percent of 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				96.00%
Secured Revolving Credit Facility [Member] | Financial Institution Borrower [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit facility amount	$ 1,550,000,000				$ 2,000,000,000
Expiration period of credit facility	1 year
Expiration date of credit facility	Jun. 29, 2018
Outstanding loan balance				$ 0

Inventories (Detail)

Inventories (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 3,094	$ 2,997
Work in process and other	2,228	2,315
Finished manufactured goods	4,188	4,179
Goods acquired for resale	6,734	6,696
Total inventory	$ 16,244	$ 16,187

Property, plant and equipment68

Property, plant and equipment and assets held for lease - Narrative (Detail) - Insurance and Other [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 23,807	$ 20,104
Property, plant and equipment, gross	43,471	37,424
Property, plant and equipment, accumulated depreciation	19,664	17,320
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	27,707	$ 21,935
ASC 606 [Member] | Aircraft Sold Under Fractional Aircraft Ownership Programs [Member]
Property, Plant and Equipment [Line Items]
Other liabilities for estimated repurchase obligations and unearned lease revenues	3,500
ASC 606 [Member] | Machinery and equipment [Member] | Aircraft Sold Under Fractional Aircraft Ownership Programs [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	3,500
Property, plant and equipment, gross	5,300
Property, plant and equipment, accumulated depreciation	$ 1,800

Property, plant and equipment69

Property, plant and equipment and assets held for lease (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Finance and Financial Products [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and assets held for lease, gross	$ 14,033	$ 13,993
Property, plant and equipment and assets held for lease, accumulated depreciation	(4,113)	(4,062)
Total property, plant and equipment and assets held for lease, net	9,920	9,931
Finance and Financial Products [Member] | Assets held for lease [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and assets held for lease, gross	12,337	12,318
Finance and Financial Products [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and assets held for lease, gross	232	231
Finance and Financial Products [Member] | Buildings, machinery and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and assets held for lease, gross	1,464	1,444
Insurance and Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	43,471	37,424
Property, plant and equipment, accumulated depreciation	(19,664)	(17,320)
Total property, plant and equipment, net	23,807	20,104
Insurance and Other [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,310	2,292
Insurance and Other [Member] | Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,961	8,810
Insurance and Other [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	27,707	21,935
Insurance and Other [Member] | Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,493	4,387
Railroad [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	71,285	70,940
Property, plant and equipment, accumulated depreciation	(8,954)	(8,627)
Total property, plant and equipment, net	62,331	62,313
Railroad [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,090	6,088
Railroad [Member] | Track structure and other roadway [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	51,652	51,320
Railroad [Member] | Locomotives, freight cars and other equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	12,600	12,543
Railroad [Member] | Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	943	989
Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	92,655	91,891
Property, plant and equipment, accumulated depreciation	(26,601)	(26,020)
Total property, plant and equipment, net	66,054	65,871
Utilities and Energy [Member] | Utility generation, transmission and distribution systems [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	75,068	74,660
Utilities and Energy [Member] | Interstate natural gas pipeline assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,230	7,176
Utilities and Energy [Member] | Independent power plants and other assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,622	7,499
Utilities and Energy [Member] | Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,735	2,556
Railroad, Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, net	$ 128,385	$ 128,184

Property, plant and equipment70

Property, plant and equipment and assets held for lease - Depreciation expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 2,035	$ 1,876
Insurance and Other [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	649	542
Railroad, Utilities and Energy [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	1,225	1,175
Finance and Financial Products [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 161	$ 159

Goodwill and other intangible71

Goodwill and other intangible assets - Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Balance at beginning of year	$ 81,258	$ 79,486
Acquisitions of businesses	52	1,545
Other, including foreign currency translation	27	227
Balance at end of period	$ 81,337	$ 81,258

Goodwill and other intangible72

Goodwill and other intangible assets - Intangible assets (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 41,310	$ 41,213
Accumulated amortization	8,391	8,031
Insurance and Other [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	40,317	40,225
Accumulated amortization	8,057	7,707
Railroad, Utilities and Energy [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	993	988
Accumulated amortization	334	324
Trademarks and trade names [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	5,394	5,381
Accumulated amortization	710	692
Customer relationships [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,353	28,322
Accumulated amortization	3,943	3,722
Other intangible assets [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,180	3,169
Accumulated amortization	1,159	1,124
Patents and technology [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Gross carrying amount	4,383	4,341
Accumulated amortization	$ 2,579	$ 2,493

Goodwill and other intangible73

Goodwill and other intangible assets - Intangible assets - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 352	$ 367
Intangible assets with indefinite lives, excluding goodwill	$ 18,900		$ 18,900

Derivative contracts (Detail)

Derivative contracts (Detail) - Finance and Financial Products [Member] - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Liabilities		$ 2,378	$ 2,172
Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member]
Derivative [Line Items]
Liabilities		2,378	2,172
Notional Value	[1]	$ 29,479	$ 28,753
[1]	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.

Derivative contracts - Gains an

Derivative contracts - Gains and losses (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains/losses	$ (206)	$ 460
Finance and Financial Products [Member] | Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains/losses	$ (206)	$ 460

Derivative contracts - Narrativ

Derivative contracts - Narrative (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finance and Financial Products [Member]
Derivative [Line Items]
Liabilities	$ 2,378,000,000	$ 2,172,000,000
Finance and Financial Products [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Collateral posting requirements under contracts with collateral provisions	0
Additional collateral posting requirements	1,100,000,000
Finance and Financial Products [Member] | Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member]
Derivative [Line Items]
Premiums received at contract inception dates	4,200,000,000
Aggregate intrinsic value of equity index put option contracts	$ 1,000,000,000	789,000,000
Weighted average remaining life of derivative contracts	2 years 8 months 12 days
Liabilities	$ 2,378,000,000	2,172,000,000
Finance and Financial Products [Member] | 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	2026-01
Finance and Financial Products [Member] | Not Designated as Hedging Instrument [Member] | Equity Index Put Options [Member] | Minimum [Member]
Derivative [Line Items]
Derivative maturity month and year	2018-06
Other Assets [Member] | Utilities and Energy [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Assets	$ 141,000,000	142,000,000
Accounts Payable, Accruals and Other Liabilities [Member] | Utilities and Energy [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liabilities	$ 105,000,000	$ 82,000,000

Supplemental cash flow inform77

Supplemental cash flow information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for income taxes	$ 289	$ 26
Liabilities assumed in connection with business acquisitions	4	142
Insurance and Other [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for interest	338	306
Railroad, Utilities and Energy [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for interest	747	737
Finance and Financial Products [Member]
Supplemental Cash Flow Information [Line Items]
Cash paid during the period for interest	$ 83	$ 78

Unpaid losses and loss adjust78

Unpaid losses and loss adjustment expenses - Reconciliation of changes in claim liabilities (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Gross liabilities at beginning of year	$ 61,122	$ 53,379
Reinsurance recoverable on unpaid losses at beginning of year	(3,201)	(3,338)
Net liabilities at beginning of year	57,921	50,041
Net liabilities at end of year	59,046	51,523
Reinsurance recoverable on unpaid losses at end of year	3,048	3,221
Gross liabilities at end of year	62,094	54,744
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	9,475	8,165
Incurred losses and loss adjustment expenses, prior accident years' events	(753)	134
Total incurred losses and loss adjustment expenses	8,722	8,299
Paid losses and loss adjustment expenses, current accident year events	(3,091)	(2,678)
Paid losses and loss adjustment expenses, prior accident years' events	(4,759)	(4,216)
Total payments	(7,850)	(6,894)
Foreign currency translation adjustment	$ 253	$ 77

Unpaid losses and loss adjust79

Unpaid losses and loss adjustment expenses - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
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 for (reductions of) prior years' accident events	$ (753)	$ 134
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	(571)	(261)
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	$ (182)	$ 395

Retroactive reinsurance contr80

Retroactive reinsurance contracts - Reconciliation of changes in claim liabilities and deferred charge assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Unpaid losses and loss adjustment expenses, beginning of year	$ 42,937	$ 24,972
Unpaid losses and loss adjustment expenses, end of year	42,344	40,587
Deferred charges reinsurance assumed, beginning of year	(15,278)	(8,047)
Deferred charges reinsurance assumed, end of year	(15,007)	(13,830)
Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and loss adjustment expenses, prior years' contracts	241	11
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		16,448
Incurred losses and loss adjustment expenses, prior years' contracts	(30)	(398)
Total incurred losses and loss adjustment expenses	(30)	16,050
Paid losses and loss adjustment expenses	(563)	(435)
Unpaid Losses and Loss Adjustment Expenses Net of Deferred Charges [Member] | Retroactive Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Total incurred losses and loss adjustment expenses	241	10,267
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		(6,192)
Incurred losses and loss adjustment expenses, prior years' contracts	271	409
Total incurred losses and loss adjustment expenses	$ 271	$ (5,783)

Retroactive reinsurance contr81

Retroactive reinsurance contracts - Narrative (Detail) - USD ($)	Feb. 02, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Effects of Reinsurance [Line Items]
Unpaid losses and loss adjustment expenses under retroactive reinsurance contracts		$ 42,344,000,000	$ 42,937,000,000	$ 40,587,000,000	$ 24,972,000,000
Deferred charges under retroactive reinsurance contracts		15,007,000,000	15,278,000,000	13,830,000,000	$ 8,047,000,000
Retroactive Reinsurance [Member]
Effects of Reinsurance [Line Items]
Incurred losses and loss adjustment expenses, prior years' contracts		241,000,000		$ 11,000,000
NICO [Member] | AIG [Member] | Retroactive Reinsurance Agreement [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
Deferred charges under retroactive reinsurance contracts	6,200,000,000	7,400,000,000	7,500,000,000
Net contract liability		$ 18,200,000,000	18,200,000,000
Increase in ultimate liabilities under reinsurance contract			$ 1,800,000,000
NICO [Member] | AIG [Member] | Retroactive Reinsurance Agreement [Member] | Maximum [Member]
Effects of Reinsurance [Line Items]
Losses and allocated loss adjustment expenses reinsured in excess of retained amount	$ 25,000,000,000

Notes payable and other borro82

Notes payable and other borrowings (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 62,667	$ 62,178
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	$ 8,627	6,452
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,048
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Subsidiaries [Member]
Debt Instrument [Line Items]
Short-term debt, weighted average interest rate	2.60%
Weighted average interest rate, percentage	4.80%
Notes payable and other borrowings	$ 28,871	28,739
Short-term debt	$ 2,608	4,488
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
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] | BNSF [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	4.70%
Notes payable and other borrowings	$ 22,561	22,499
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | BNSF [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
Railroad, Utilities and Energy [Member] | Subsidiaries [Member] | BNSF [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,097
Finance and Financial Products [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 10,755	13,085
Finance and Financial Products [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	3.10%
Notes payable and other borrowings	$ 10,578	12,926
Finance and Financial Products [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
Finance and Financial Products [Member] | Subsidiaries [Member] | Berkshire Hathaway Finance Corporation [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,043
Finance and Financial Products [Member] | Subsidiaries [Member] | Other Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	4.00%
Notes payable and other borrowings	$ 177	159
Finance and Financial Products [Member] | Subsidiaries [Member] | Other Subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,019
Finance and Financial Products [Member] | Subsidiaries [Member] | Other Subsidiaries [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,028
Insurance and Other [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 25,663	27,324
Insurance and Other [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Short-term debt, weighted average interest rate	3.70%
Weighted average interest rate, percentage	4.00%
Short-term debt	$ 1,800	1,832
Other borrowings	$ 5,676	6,725
Insurance and Other [Member] | Subsidiaries [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
Insurance and Other [Member] | Subsidiaries [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2,045
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	3.00%
Notes payable and other borrowings	$ 9,804	10,603
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Euro Denominated [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	1.10%
Notes payable and other borrowings	$ 8,383	$ 8,164
Insurance and Other [Member] | Berkshire Hathaway Inc. (Parent) [Member] | Minimum [Member] | U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Debt maturity year	2,018
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

Notes payable and other borro83

Notes payable and other borrowings - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Jan. 31, 2018
Insurance and Other [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	4.00%
Insurance and Other [Member] | Euro Denominated [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	1.10%
Insurance and Other [Member] | Euro Denominated [Member] | Senior Notes [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Increase in carrying value of notes	$ 217
Insurance and Other [Member] | Euro Denominated [Member] | Senior Notes [Member] | Interest Expense [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Revaluation attributable to changes in foreign currency exchange rates	217
Insurance and Other [Member] | U.S. Dollar Denominated [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Repayments of borrowings	$ 800
Weighted average interest rate, percentage	3.00%
Berkshire Hathaway Energy Company and Subsidiaries [Member] | Railroad, Utilities and Energy [Member] | Debt Due 2021 to 2048 [Member] | Senior Notes [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 2,200
Weighted average interest rate, percentage		3.20%
BNSF [Member] | Railroad, Utilities and Energy [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Repayments of borrowings	$ 650
Weighted average interest rate, percentage	4.70%
BNSF [Member] | Railroad, Utilities and Energy [Member] | Debentures Due 2048 at 4.05% [Member] | Senior Unsecured Debentures [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 750
Debt instrument, interest rate, stated percentage	4.05%
Berkshire Hathaway Finance Corporation [Member] | Finance and Financial Products [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	3.10%
Berkshire Hathaway Finance Corporation [Member] | Finance and Financial Products [Member] | Senior Notes [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Repayments of borrowings	$ 2,350

Notes payable and other borro84

Notes payable and other borrowings - Credit agreements - Narrative (Detail) $ in Billions	Mar. 31, 2018USD ($)
Line of Credit and Commercial Paper Facilities [Member] | Subsidiaries [Member]
Line of Credit Facility [Line Items]
Unused lines of credit available	$ 7.3
Line of Credit and Commercial Paper Facilities [Member] | Subsidiaries [Member] | Berkshire Hathaway Energy Company and Subsidiaries [Member]
Line of Credit Facility [Line Items]
Unused lines of credit available	5.3
Subsidiaries Excluding Berkshire Hathaway Finance Corporation [Member] | Berkshire Hathaway Inc. (Parent) [Member]
Line of Credit Facility [Line Items]
Guarantee obligation	$ 1.9

Fair value measurements - Finan

Fair value measurements - Financial assets and liabilities (Detail) - USD ($) $ in Millions		Mar. 31, 2018		Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		$ 19,920		$ 21,353
Investments in equity securities		172,976	[1]	170,540	[2]
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		62,667		62,178
Insurance and Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		19,920		21,353
Investments in equity securities		166,658		164,026
Investment in Kraft Heinz common stock - carrying value		17,687		17,635
Investment in Kraft Heinz common stock - fair value		20,272		25,306
Notes payable and other borrowings - carrying value		25,663		27,324
Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and finance receivables - carrying value		13,845		13,748
Derivative contract liabilities		2,378		2,172
Notes payable and other borrowings - carrying value		10,755		13,085
Significant Unobservable Inputs (Level 3) [Member] | Equity Index Put Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities		2,378
Other Assets [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities	[3]	1,755		1,961
Other Assets [Member] | Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in equity securities	[3]	4,563		4,553
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		3,608		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		759		854
Foreign governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		7,888		8,822
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		6,819		6,862
Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in fixed maturity securities		846		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		172,928		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		48		46
Loans and finance receivables - fair value		18		17
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [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		68,603		70,538
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [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		26,046		28,180
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		11,035		13,577
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and finance receivables - fair value		14,066		14,119
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		24		5
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity Index Put Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities		2,378		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	[4]	1		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	[4]	26		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	[4]	114		113
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Quoted Prices (Level 1) [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[4]			3
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[4]	88		69
Fair Value, Measurements, Recurring [Member] | Accounts Payable, Accruals and Other Liabilities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Railroad, Utilities and Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative contract liabilities	[4]	17		10
Fair Value, Measurements, Recurring [Member] | Kraft Heinz (previously Heinz Holding) [Member] | Quoted Prices (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Kraft Heinz common stock - fair value		20,272		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		2,399		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		1,209		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		759		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		5,906		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		1,982		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		6,813		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		846		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		172,976		170,540
Loans and finance receivables - carrying value		13,845		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		62,667		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		25,663		27,324
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - carrying value		10,755		13,085
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		2,378		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	[4]	141		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	[4]	105		82
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Kraft Heinz (previously Heinz Holding) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Kraft Heinz common stock - carrying value		17,687		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		3,608		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		759		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		7,888		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		6,819		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		846		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		172,976		170,540
Loans and finance receivables - fair value		14,084		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		68,603		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		26,046		28,180
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Finance and Financial Products [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable and other borrowings - fair value		11,059		13,582
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		2,378		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	[4]	141		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	[4]	105		82
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Kraft Heinz (previously Heinz Holding) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Kraft Heinz common stock - fair value		20,272		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		3,608		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		759		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		7,888		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		6,819		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		$ 846		$ 862
[1]	Approximately 68% of the aggregate fair value was concentrated in five companies (American Express Company - $14.1 billion; Apple Inc. - $40.7 billion; Bank of America Corporation - $21.0 billion; The Coca-Cola Company - $17.4 billion and Wells Fargo & Company - $25.2 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]	Included in other assets.
[4]	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	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value Measurements Significant Unobservable Inputs [Line Items]
Net derivative contract liabilities - Beginning Balance	$ (2,069)	$ (2,824)
Net derivative contract liabilities - Gains (losses) included in earnings	(176)	499
Net derivative contract liabilities - Gains (losses) included in other comprehensive income	(1)	(2)
Net derivative contract liabilities - Gains (losses) included in regulatory assets and liabilities	(9)	1
Net derivative contract liabilities - Acquisitions, dispositions and settlements	(26)	(23)
Net derivative contract liabilities - Ending Balance	(2,281)	(2,349)
Fixed Maturities and Equity Securities [Member]
Fair Value Measurements Significant Unobservable Inputs [Line Items]
Beginning Balance	6	17,321
Gains (losses) included in other comprehensive income		1,157
Acquisitions, dispositions and settlements		(3)
Transfers into/out of Level 3		(1)
Ending Balance	$ 6	$ 18,474

Fair value measurements - Other

Fair value measurements - Other information (Detail) - Significant Unobservable Inputs (Level 3) [Member] - Equity Index Put Options [Member] $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Derivative contract liabilities, fair value	$ 2,378
Principal valuation techniques	Option pricing model
Unobservable inputs, volatility, weighted average	18.00%

Common stock (Detail)

Common stock (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Class A [Member]
Class of Stock [Line Items]
Shares issued	759,717	762,755
Treasury shares	(11,680)	(11,680)
Shares outstanding	748,037	751,075
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition	(3,038)
Class B [Member]
Class of Stock [Line Items]
Shares issued	1,346,872,832	1,342,066,749
Treasury shares	(1,409,762)	(1,409,762)
Shares outstanding	1,345,463,070	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	4,806,083

Common stock (Parenthetical) (D

Common stock (Parenthetical) (Detail)	Mar. 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

Common stock - Narrative (Detai

Common stock - Narrative (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)Voteshares	Dec. 31, 2017shares
Class of Stock [Line Items]
Preferred Stock, shares authorized	1,000,000
Preferred Stock, shares issued	0
Class B [Member]
Class of Stock [Line Items]
Ratio of net earnings per equivalent common share and dividend and distribution rights of Class B shares to Class A shares	0.000667
Number of votes entitled per share, number | Vote	0.0001
Number of shares of Class B stock obtainable from converting one Class A share	1,500
Shares outstanding	1,345,463,070	1,340,656,987
Class A [Member]
Class of Stock [Line Items]
Number of votes entitled per share, number | Vote	1
Shares outstanding	748,037	751,075
Equivalent Class A [Member]
Class of Stock [Line Items]
Shares outstanding	1,645,012	1,644,846
Common Stock Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase, authorization description	Berkshire's Board of Directors has approved a common stock repurchase program permitting 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
Minimum cash, cash equivalents and U.S. Treasury Bills threshold after repurchase of common stock shares, amount | $	$ 20,000,000,000

Accumulated other comprehensi91

Accumulated other comprehensive income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 351,954	$ 285,428
Ending Balance	351,052	295,349
Unrealized appreciation of investments, net [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	62,093	43,176
Reclassifications to retained earnings	(61,340)
Other comprehensive income, net before reclassifications	(74)	5,497
Reclassifications into net earnings	(175)	(198)
Ending Balance	504	48,475
Foreign currency translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,114)	(5,268)
Reclassifications to retained earnings	(65)
Other comprehensive income, net before reclassifications	585	475
Ending Balance	(2,594)	(4,793)
Prior service and actuarial gains/losses of defined benefit pension plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(420)	(593)
Reclassifications to retained earnings	36
Other comprehensive income, net before reclassifications	(17)	(22)
Reclassifications into net earnings	9	18
Ending Balance	(392)	(597)
Other AOCI transactions [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	12	(17)
Reclassifications to retained earnings	(6)
Other comprehensive income, net before reclassifications	2	(6)
Reclassifications into net earnings	(3)	8
Ending Balance	5	(15)
Accumulated other comprehensive income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	58,571	37,298
Reclassifications to retained earnings	(61,375)
Other comprehensive income, net before reclassifications	496	5,944
Reclassifications into net earnings	(169)	(172)
Ending Balance	$ (2,477)	$ 43,070

Accumulated other comprehensi92

Accumulated other comprehensive income - Reclassified Amounts (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Unrealized appreciation of investments, net [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before income taxes	$ (221)	$ (305)
Applicable income taxes	(46)	(107)
Total reclassifications into net earnings	(175)	(198)
Prior service and actuarial gains/losses of defined benefit pension plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before income taxes	10	24
Applicable income taxes	1	6
Total reclassifications into net earnings	9	18
Other AOCI transactions [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before income taxes	(5)	14
Applicable income taxes	(2)	6
Total reclassifications into net earnings	(3)	8
Accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before income taxes	(216)	(267)
Applicable income taxes	(47)	(95)
Total reclassifications into net earnings	$ (169)	$ (172)

Contingencies and Commitments -

Contingencies and Commitments - Narrative (Detail) $ in Billions	3 Months Ended
	Sep. 30, 2018USD ($)
Scenario, Forecast [Member] | NICO [Member] | Purchase Agreement [Member] | Medical Liability Mutual Insurance Company [Member]
Contingencies and Commitments [Line Items]
Acquisition price	$ 2.5

Business segment data - Revenue

Business segment data - Revenues by segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 58,473	$ 64,370
BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,590
Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Total revenues	4,512
Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	12,912
McLane Company [Member]
Segment Reporting Information [Line Items]
Total revenues	12,189
Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	6,560
Finance and Financial Products Reportable Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	2,060
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	58,495	64,441
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Interest, dividend and other investment income	1,213	1,132
Total revenues	14,586	22,885
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member]
Segment Reporting Information [Line Items]
Premiums earned	7,915	6,845
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Reinsurance Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	3,540	13,232
Operating Businesses [Member] | Insurance Group [Member] | Berkshire Hathaway Primary Group [Member]
Segment Reporting Information [Line Items]
Premiums earned	1,918	1,676
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Total revenues	5,624	5,185
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Total revenues	4,512	4,231
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	12,934	12,097
Operating Businesses [Member] | McLane Company [Member]
Segment Reporting Information [Line Items]
Total revenues	12,189	12,101
Operating Businesses [Member] | Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Total revenues	6,587	6,093
Operating Businesses [Member] | Finance and Financial Products Reportable Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	2,063	1,849
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (22)	$ (71)

Business segment data - Earning

Business segment data - Earnings before income taxes by segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Investment and derivative gains/losses	$ (8,015)	$ 775
Earnings (loss) before income taxes	(1,523)	5,688
Operating Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	6,647	5,102
Operating Businesses [Member] | Insurance Group [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	1,723	750
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	1,205	1,129
Operating Businesses [Member] | Insurance Group [Member] | GEICO [Member] | Insurance Premiums Earned [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	677	175
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	(258)	(743)
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	99	189
Operating Businesses [Member] | BNSF [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	1,513	1,345
Operating Businesses [Member] | Berkshire Hathaway Energy [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	487	589
Operating Businesses [Member] | Manufacturing Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	1,855	1,487
Operating Businesses [Member] | McLane Company [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	60	88
Operating Businesses [Member] | Service and Retailing Businesses [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	515	393
Operating Businesses [Member] | Finance and Financial Products Reportable Segment [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	494	450
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Investment and derivative gains/losses	(8,015)	775
Interest expense	(337)	(211)
Equity method investments	401	281
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes from operating businesses	$ (219)	$ (259)