Year the debt matures, in CCYY format.

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Aggregate amount of short-term and long-term debt maturing or scheduled to be repaid within the next twelve months following the date of the latest balance sheet presented in the financial statements.

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

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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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Weighted average interest rate of debt outstanding.

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No definition available.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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Notes payable and other borrowings (Detail) € in Millions, £ in Millions, $ in Millions, ¥ in Billions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 JPY (¥)	Dec. 31, 2020 GBP (£)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Notes payable and other borrowings		€ 6,850	¥ 625.5	£ 1,750
Principal payments on debt - 2021	$ 9,398
Principal payments on debt - 2022	4,998
Principal payments on debt - 2023	10,813
Principal payments on debt - 2024	6,308
Principal payments on debt - 2025	6,594
Insurance and Other [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	41,522				$ 37,590
Principal payments on debt - 2021	4,354
Principal payments on debt - 2022	1,593
Principal payments on debt - 2023	6,021
Principal payments on debt - 2024	2,343
Principal payments on debt - 2025	2,817
Railroad, Utilities and Energy [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	75,373				65,778
Principal payments on debt - 2021	5,044
Principal payments on debt - 2022	3,405
Principal payments on debt - 2023	4,792
Principal payments on debt - 2024	3,965
Principal payments on debt - 2025	3,777
Berkshire Hathaway Inc. (Parent) [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	22,665				19,903
Principal payments on debt - 2021	2,172
Principal payments on debt - 2022	600
Principal payments on debt - 2023	4,633
Principal payments on debt - 2024	2,272
Principal payments on debt - 2025	1,801
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 8,308				8,324
Weighted average interest rate, percentage	3.20%	3.20%	3.20%	3.20%
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2047
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Euro Denominated [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 8,326				7,641
Weighted average interest rate, percentage	1.00%	1.00%	1.00%	1.00%
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Euro Denominated [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Euro Denominated [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2035
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Japanese Yen Denominated [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 6,031				3,938
Weighted average interest rate, percentage	0.70%	0.70%	0.70%	0.70%
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Japanese Yen Denominated [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2023
Berkshire Hathaway Inc. (Parent) [Member] \| Insurance and Other [Member] \| Japanese Yen Denominated [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2060
Subsidiaries [Member] \| Insurance and Other [Member]
Debt Instrument [Line Items]
Other borrowings	$ 4,682				5,262
Short-term debt	$ 1,062				1,472
Weighted average interest rate, percentage	4.20%	4.20%	4.20%	4.20%
Short-term debt, weighted average interest rate	2.50%	2.50%	2.50%	2.50%
Subsidiaries [Member] \| Insurance and Other [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Subsidiaries [Member] \| Insurance and Other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2045
Subsidiaries [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 10,766				8,679
Weighted average interest rate, percentage	3.70%	3.70%	3.70%	3.70%
Subsidiaries [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Subsidiaries [Member] \| Insurance and Other [Member] \| U.S. Dollar Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2050
Subsidiaries [Member] \| Insurance and Other [Member] \| Great Britain Pound Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 2,347				2,274
Weighted average interest rate, percentage	2.50%	2.50%	2.50%	2.50%
Subsidiaries [Member] \| Insurance and Other [Member] \| Great Britain Pound Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2039
Subsidiaries [Member] \| Insurance and Other [Member] \| Great Britain Pound Denominated [Member] \| Berkshire Hathaway Finance Corporation [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2059
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy [Member]
Debt Instrument [Line Items]
Weighted average interest rate, percentage	4.20%	4.20%	4.20%	4.20%
Senior unsecured debt	$ 13,447				8,581
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2051
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy Subsidiaries [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 36,420				30,772
Weighted average interest rate, percentage	4.10%	4.10%	4.10%	4.10%
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy Subsidiaries [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy Subsidiaries [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2064
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Berkshire Hathaway Energy and Subsidiaries [Member]
Debt Instrument [Line Items]
Short-term debt	$ 2,286				3,214
Short-term debt, weighted average interest rate	1.80%	1.80%	1.80%	1.80%
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Burlington Northern Santa Fe ("BNSF") and subsidiaries [Member]
Debt Instrument [Line Items]
Notes payable and other borrowings	$ 23,220				$ 23,211
Weighted average interest rate, percentage	4.60%	4.60%	4.60%	4.60%
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Burlington Northern Santa Fe ("BNSF") and subsidiaries [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt maturity year	2021
Subsidiaries [Member] \| Railroad, Utilities and Energy [Member] \| Burlington Northern Santa Fe ("BNSF") and subsidiaries [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt maturity year	2097