Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021		Sep. 30, 2020
Cash flows from operating activities:
Net earnings	$ 50,909		$ 7,123
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(37,235)		(2,032)
Depreciation and amortization	8,013		7,692
Other, including asset impairment charges	(717)		10,934
Changes in operating assets and liabilities:
Losses and loss adjustment expenses	4,809		4,480
Deferred charges reinsurance assumed	709		735
Unearned premiums	3,958		2,544
Receivables and originated loans	(6,810)		(3,223)
Other assets	(1,558)		(1,673)
Other liabilities	1,928		2,446
Income taxes	7,620		201
Net cash flows from operating activities	31,626		29,227
Cash flows from investing activities:
Purchases of equity securities	(5,004)		(22,406)
Sales of equity securities	11,975		28,564
Purchases of U.S. Treasury Bills and fixed maturity securities	(106,399)		(153,897)
Sales of U.S. Treasury Bills and fixed maturity securities	15,945		23,744
Redemptions and maturities of U.S. Treasury Bills and fixed maturity securities	103,294		81,252
Purchases of loans and finance receivables	(70)		(619)
Collections of loans and finance receivables	283		268
Acquisitions of businesses, net of cash acquired	(204)		(111)
Purchases of property, plant and equipment and equipment held for lease	(9,244)		(9,516)
Other	1,505		(1,685)
Net cash flows from investing activities	12,081		(54,406)
Cash flows from financing activities:
Changes in short term borrowings, net	(689)		(1,062)
Acquisition of treasury stock	(20,192)		(15,712)
Other	(755)		(196)
Net cash flows from financing activities	(21,364)		(11,676)
Effects of foreign currency exchange rate changes	(98)		(340)
Increase (decrease) in cash and cash equivalents and restricted cash	22,245		(37,195)
Cash and cash equivalents and restricted cash at beginning of year*	48,396		64,632
Cash and cash equivalents and restricted cash at end of third quarter*	70,641		27,437
Restricted cash, included in other assets at beginning of year	406		457
Restricted cash, included in other assets at end of third quarter	$ 652		$ 620
Restricted Cash and Cash Equivalents, Asset, Statement of Financial Position [Extensible List]	Other		Other
Insurance and Other [Member]
Cash flows from financing activities:
Proceeds from borrowings	$ 2,952		$ 3,435
Repayments of borrowings	(3,010)		(2,116)
Cash and cash equivalents at beginning of year	44,714	[1]	61,151
Cash and cash equivalents at end of third quarter	65,156	[1]	23,078
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	2,939		6,424
Repayments of borrowings	(2,609)		(2,449)
Cash and cash equivalents at beginning of year	3,276	[1]	3,024
Cash and cash equivalents at end of third quarter	$ 4,833	[1]	$ 3,739

[1] Includes U.S. Treasury Bills with maturities of three months or less when purchased of $37.9 billion at September 30, 2021 and $23.2 billion at December 31, 2020.