Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025		Mar. 31, 2024
Cash flows from operating activities:
Net earnings	$ 4,672		$ 12,832
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	6,435		(1,876)
Depreciation and amortization	3,265		3,168
Discount accretion on investments, principally U.S. Treasury Bills	(3,129)		(1,908)
Other	1,504		(955)
Changes in operating assets and liabilities:
Unpaid losses and loss adjustment expenses	1,215		117
Deferred charges - retroactive reinsurance	169		177
Unearned premiums	1,451		1,494
Receivables and originated loans	(3,295)		469
Inventories	103		516
Other assets	(400)		(415)
Other liabilities	(1,291)		(5,486)
Income taxes	204		2,433
Net cash flows from operating activities	10,903		10,566
Cash flows from investing activities:
Purchases of equity securities	(3,183)		(2,691)
Sales of equity securities	4,677		19,972
Purchases of U.S. Treasury Bills and fixed maturity securities	(158,722)		(103,167)
Sales of U.S. Treasury Bills and fixed maturity securities	6,286		7,452
Redemptions and maturities of U.S. Treasury Bills and fixed maturity securities	138,620		80,114
Purchases of property, plant and equipment and equipment held for lease	(4,281)		(4,393)
Other	202		(490)
Net cash flows from investing activities	(16,401)		(3,203)
Cash flows from financing activities:
Changes in short term borrowings, net	(415)		(2,612)
Acquisitions of treasury stock			(2,562)
Other, principally transactions with noncontrolling interests	(143)		(2,664)
Net cash flows from financing activities	53		(9,802)
Effects of foreign currency exchange rate changes	(76)		(44)
Increase (decrease) in cash and cash equivalents and restricted cash	(5,521)		(2,483)
Cash and cash equivalents and restricted cash at the beginning of the year	48,376		38,643
Cash and cash equivalents and restricted cash at the end of the first quarter	42,855		36,160
Restricted cash included in other assets at the beginning of the year	647		621
Restricted cash included in other assets at the end of the first quarter	$ 675		$ 611
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	$ (1,299)		$ (6,938)
Cash and cash equivalents at beginning of the year	44,333	[1]	34,268
Cash and cash equivalents at the end of the first quarter	36,892	[1]	29,303
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	2,353		5,084
Repayments of borrowings	(443)		(110)
Cash and cash equivalents at beginning of the year	3,396	[1]	3,754
Cash and cash equivalents at the end of the first quarter	$ 5,288	[1]	$ 6,246

[1] Includes U.S. Treasury Bills with maturities of three months or less when purchased of $8.6 billion at March 31, 2025 and $14.4 billion at December 31, 2024.