Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024		Mar. 31, 2023
Cash flows from operating activities:
Net earnings	$ 12,832		$ 35,757
Adjustments to reconcile net earnings (loss) to operating cash flows:
Investment (gains) losses	(1,876)		(34,758)
Depreciation and amortization	3,168		3,051
Other	(2,863)		(1,293)
Changes in operating assets and liabilities:
Unpaid losses and loss adjustment expenses	117		22
Deferred charges - retroactive reinsurance	177		172
Unearned premiums	1,494		1,686
Receivables and originated loans	469		(922)
Inventories	516		(15)
Other assets	(415)		(987)
Other liabilities	(5,486)		2,649
Income taxes	2,433		8,629
Net cash flows from operating activities	10,566		8,693
Cash flows from investing activities:
Purchases of equity securities	(2,691)		(2,873)
Sales of equity securities	19,972		13,283
Purchases of U.S. Treasury Bills and fixed maturity securities	(103,167)		(45,515)
Sales of U.S. Treasury Bills and fixed maturity securities	7,452		12,982
Redemptions and maturities of U.S. Treasury Bills and fixed maturity securities	80,114		25,364
Acquisitions of businesses, net of cash acquired	(327)		(7,629)
Purchases of property, plant and equipment and equipment held for lease	(4,393)		(3,713)
Other	(163)		182
Net cash flows from investing activities	(3,203)		(7,919)
Cash flows from financing activities:
Changes in short term borrowings, net	(2,612)		1,098
Acquisitions of treasury stock	(2,562)		(4,450)
Other, principally transactions with noncontrolling interests	(2,664)		(380)
Net cash flows from financing activities	(9,802)		(9,922)
Effects of foreign currency exchange rate changes	(44)		(47)
Increase (decrease) in cash and cash equivalents and restricted cash	(2,483)		(9,101)
Cash and cash equivalents and restricted cash at the beginning of the year	38,643		36,399
Cash and cash equivalents and restricted cash at the end of the first quarter	36,160		27,298
Restricted cash, included in other assets at the beginning of the year	621		588
Restricted cash, included in other assets at the end of the first quarter	$ 611		$ 551
Restricted Cash and Cash Equivalents, Asset, Statement of Financial Position [Extensible List]	Other		Other
Insurance and Other [Member]
Cash flows from financing activities:
Repayments of borrowings	$ (1,142)		$ (4,946)
Cash and cash equivalents at beginning of the year	33,672	[1]	32,260
Cash and cash equivalents at the end of the first quarter	28,891	[1]	23,805
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	5,084
Repayments of borrowings	(5,906)		(1,244)
Cash and cash equivalents at beginning of the year	4,350	[1]	3,551
Cash and cash equivalents at the end of the first quarter	$ 6,658	[1]	$ 2,942

[1] Includes U.S. Treasury Bills with maturities of three months or less when purchased of $4.0 billion at March 31, 2024 and $4.8 billion at December 31, 2023.