Common stock (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Changes in issued, treasury and outstanding Berkshire common stock

The changes in Berkshire’s issued, treasury and outstanding common stock for each of the three years ending December 31, 2023 are shown in the table below. In addition, 1,000,000 shares of preferred stock are authorized, but none are issued.

	Class A, $5 Par Value (1,650,000 shares authorized)									Class B, $0.0033 Par Value (3,225,000,000 shares authorized)
	Issued			Treasury			Outstanding			Issued		Treasury			Outstanding
Balance at December 31, 2020		678,523			(34,592	)		643,931			1,469,359,852		(119,316,381	)		1,350,043,471
Conversions of Class A to    Class B common stock		(12,622	)		—			(12,622	)		18,933,000		—			18,933,000
Treasury stock acquired		—			(14,196	)		(14,196	)		—		(78,501,968	)		(78,501,968	)
Balance at December 31, 2021		665,901			(48,788	)		617,113			1,488,292,852		(197,818,349	)		1,290,474,503
Conversions of Class A to    Class B common stock		(14,451	)		—			(14,451	)		21,676,500		—			21,676,500
Treasury stock acquired		—			(11,098	)		(11,098	)		—		(9,896,927	)		(9,896,927	)
Balance at December 31, 2022		651,450			(59,886	)		591,564			1,509,969,352		(207,715,276	)		1,302,254,076
Conversions of Class A to    Class B common stock		(12,122	)		—			(12,122	)		18,183,000		—			18,183,000
Treasury stock acquired		—			(11,667	)		(11,667	)		—		(9,875,568	)		(9,875,568	)
Balance at December 31, 2023		639,328			(71,553	)		567,775			1,528,152,352		(217,590,844	)		1,310,561,508