The principal amount of new debt issued during the period, excluding premium or discount, if any.

No definition available.

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- Definition

The increase (decrease) during the reporting period in obligations evidenced by formal promissory notes.

+ References

No definition available.

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- Definition

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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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.

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No definition available.

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- Definition

Weighted average interest rate of debt outstanding.

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No definition available.

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- Definition

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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Notes payable and other borrowings - Narrative (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 31, 2018	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Insurance and Other [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage		4.00%	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%	1.10%
Insurance and Other [Member] \| Euro Denominated [Member] \| Senior Notes [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Increase (decrease) in carrying value of notes			$ (273)	$ 860
Insurance and Other [Member] \| Euro Denominated [Member] \| Senior Notes [Member] \| Interest Expense [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Increase (decrease) in interest expense attributable to changes in foreign currency exchange rates			(273)	$ 860
Berkshire Hathaway Energy and Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Debt Due 2020 To 2049 [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 2,050	$ 5,500
Weighted average interest rate, percentage		3.60%	3.60%
BNSF [Member] \| Railroad, Utilities and Energy [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage		4.70%	4.70%
Repayments of borrowings			$ 650
BNSF [Member] \| Railroad, Utilities and Energy [Member] \| Senior Unsecured Debentures [Member] \| Debentures Due 2048 [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 750	$ 1,500
Weighted average interest rate, percentage		4.10%	4.10%
Berkshire Hathaway Finance Corporation [Member] \| Finance and Financial Products [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage		3.30%	3.30%
Berkshire Hathaway Finance Corporation [Member] \| Finance and Financial Products [Member] \| Senior Notes [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Repayments of borrowings			$ 4,600
Berkshire Hathaway Finance Corporation [Member] \| Finance and Financial Products [Member] \| Senior Notes [Member] \| Notes Due 2048 at 4.2% [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 2,350
Debt instrument, interest rate, stated percentage	4.20%