Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	na
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64836518&loc=d3e30700-110894

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64836518&loc=d3e30690-110894

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Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

Notes payable and other borrowings - Narrative (Detail) € in Millions, $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended
	May 31, 2017 USD ($)	Jan. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jan. 31, 2017 EUR (€)	Jan. 31, 2017 USD ($)
Berkshire Hathaway Inc. (Parent) [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Repayments of borrowings		$ 1,100
Berkshire Hathaway Inc. (Parent) [Member] \| Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Principal amount of debt issued \| €						€ 1,100
Berkshire Hathaway Inc. (Parent) [Member] \| Senior Unsecured Notes [Member] \| Notes Due 2021 at 0.25% [Member]
Debt Instrument [Line Items]
Principal amount of debt issued \| €						€ 550
Debt instrument, interest rate, stated percentage						0.25%	0.25%
Berkshire Hathaway Inc. (Parent) [Member] \| Senior Unsecured Notes [Member] \| Notes Due 2023 at 0.625% [Member]
Debt Instrument [Line Items]
Principal amount of debt issued \| €						€ 550
Debt instrument, interest rate, stated percentage						0.625%	0.625%
Berkshire Hathaway Inc. (Parent) [Member] \| Interest Expense [Member] \| Senior Notes [Member] \| Euro Denominated [Member]
Debt Instrument [Line Items]
Revaluation attributable to changes in foreign currency exchange rates			$ 526	$ 597
Finance and Financial Products [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage			2.70%	2.70%
Finance and Financial Products [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount of debt issued							$ 1,300
Repayments of borrowings				$ 2,400
Finance and Financial Products [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Senior Notes [Member] \| Notes Due 2019, Floating Rate [Member]
Debt Instrument [Line Items]
Principal amount of debt issued							950
Finance and Financial Products [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Senior Notes [Member] \| Notes Due 2020, Floating Rate [Member]
Debt Instrument [Line Items]
Principal amount of debt issued							$ 350
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy Company and Subsidiaries [Member] \| Debt Due 2027 to 2057 [Member]
Debt Instrument [Line Items]
Principal amount of debt issued			$ 1,275	$ 1,275
Weighted average interest rate, percentage			3.70%	3.70%
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| BNSF [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage			4.80%	4.80%
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| BNSF [Member] \| Senior Unsecured Debentures [Member]
Debt Instrument [Line Items]
Principal amount of debt issued					$ 1,250
Repayments of borrowings	$ 650
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| BNSF [Member] \| Senior Unsecured Debentures [Member] \| Debentures Due 2027 at 3.25% [Member]
Debt Instrument [Line Items]
Principal amount of debt issued					$ 500
Debt instrument, interest rate, stated percentage					3.25%
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| BNSF [Member] \| Senior Unsecured Debentures [Member] \| Debentures Due 2047 at 4.125% [Member]
Debt Instrument [Line Items]
Principal amount of debt issued					$ 750
Debt instrument, interest rate, stated percentage					4.125%