Year the debt matures, in CCYY format.

No definition available.

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- Definition

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

+ References

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount of short-term and long-term debt and lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

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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.

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 1
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Balance Type:	credit
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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
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- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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Notes payable and other borrowings - Narrative (Detail) € in Millions, £ in Millions, $ in Millions, ¥ in Billions		1 Months Ended				3 Months Ended		9 Months Ended
	Oct. 29, 2020 USD ($)	Oct. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Apr. 30, 2020 JPY (¥)	Mar. 31, 2020 EUR (€)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 EUR (€)	Sep. 30, 2020 JPY (¥)	Sep. 30, 2020 GBP (£)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Notes payable and other borrowings										€ 6,850	¥ 625.5	£ 1,750
Insurance and Other [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings						$ 38,891		$ 38,891					$ 37,590
Insurance and Other [Member] \| Berkshire Hathaway Inc. (Parent) [Member] \| Subsidiaries Excluding Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Guarantee obligation						$ 1,200		$ 1,200
Insurance and Other [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage						4.20%		4.20%		4.20%	4.20%	4.20%
Insurance and Other [Member] \| Subsidiaries [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year								2020
Insurance and Other [Member] \| Subsidiaries [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year								2045
Insurance and Other [Member] \| Senior Notes [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Gains (losses) attributable to changes in foreign currency exchange rates						$ (549)	$ 383	$ (447)	$ 447
Insurance and Other [Member] \| Senior Notes [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Repayments of borrowings								350
Insurance and Other [Member] \| Senior Notes [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of borrowings		$ 550
Principal amount of debt issued		2,500
Insurance and Other [Member] \| Senior Notes [Member] \| Notes Due 2025 at 0.0% [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Repayments of borrowings \| €					€ 1,000
Principal amount of debt issued \| €					€ 1,000
Debt instrument, interest rate, stated percentage					0.00%
Debt maturity year					2025
Insurance and Other [Member] \| Senior Notes [Member] \| Debt Due 2023 To 2060 [Member] \| Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Principal amount of debt issued			$ 1,800	¥ 195.5
Weighted average interest rate, percentage			1.07%	1.07%
Insurance and Other [Member] \| Senior Notes [Member] \| Debt Due 2023 To 2060 [Member] \| Berkshire Hathaway Inc. (Parent) [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year			2023	2023
Insurance and Other [Member] \| Senior Notes [Member] \| Debt Due 2023 To 2060 [Member] \| Berkshire Hathaway Inc. (Parent) [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year			2060	2060
Insurance and Other [Member] \| Senior Notes [Member] \| Notes Due 2030 at 1.85% [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Principal amount of debt issued								$ 500
Debt instrument, interest rate, stated percentage						1.85%		1.85%		1.85%	1.85%	1.85%
Debt maturity year								2030
Insurance and Other [Member] \| Senior Notes [Member] \| Notes Due 2030 at 1.45% [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 750
Debt instrument, interest rate, stated percentage		1.45%
Debt maturity year		2030
Insurance and Other [Member] \| Senior Notes [Member] \| Notes Due 2050 at 2.85% [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Principal amount of debt issued		$ 1,750
Debt instrument, interest rate, stated percentage		2.85%
Debt maturity year		2050
Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings						$ 68,800		$ 68,800					$ 65,778
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Repayments of borrowings								$ 1,900
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage						4.50%		4.50%		4.50%	4.50%	4.50%
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| Minimum [Member] \| Berkshire Hathaway Energy [Member]
Debt Instrument [Line Items]
Debt maturity year								2021
Railroad, Utilities and Energy [Member] \| Subsidiaries [Member] \| Maximum [Member] \| Berkshire Hathaway Energy [Member]
Debt Instrument [Line Items]
Debt maturity year								2050
Railroad, Utilities and Energy [Member] \| Debt Due 2025 To 2062 [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Principal amount of debt issued								$ 5,500
Weighted average interest rate, percentage						3.40%		3.40%		3.40%	3.40%	3.40%
Railroad, Utilities and Energy [Member] \| Debt Due 2025 To 2062 [Member] \| Subsidiaries [Member] \| Minimum [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Debt maturity year								2025
Railroad, Utilities and Energy [Member] \| Debt Due 2025 To 2062 [Member] \| Subsidiaries [Member] \| Maximum [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Debt maturity year								2062
Railroad, Utilities and Energy [Member] \| Senior Notes [Member] \| Notes Due 2031 at 1.65% [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 500
Debt instrument, interest rate, stated percentage	1.65%
Debt maturity year	2031
Railroad, Utilities and Energy [Member] \| Senior Notes [Member] \| Notes Due 2051 at 2.85% [Member] \| Subsidiaries [Member] \| Berkshire Hathaway Energy [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Principal amount of debt issued	$ 1,500
Debt instrument, interest rate, stated percentage	2.85%
Debt maturity year	2051
Railroad, Utilities and Energy [Member] \| Senior Unsecured Debenture [Member] \| Debentures Due 2051 [Member] \| Subsidiaries [Member] \| BNSF [Member]
Debt Instrument [Line Items]
Repayments of borrowings								$ 541
Principal amount of debt issued			$ 575
Debt instrument, interest rate, stated percentage			3.05%	3.05%
Debt maturity year			2051	2051