Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net earnings	$ 14,782	$ 10,651
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(2,711)	(936)
Depreciation	4,036	3,814
Other	983	641
Changes in operating assets and liabilities before business acquisitions:
Losses and loss adjustment expenses	682	(435)
Deferred charges reinsurance assumed	(203)	204
Unearned premiums	1,432	2,136
Receivables and originated loans	(359)	(1,759)
Derivative contract assets and liabilities	(1,927)	(104)
Income taxes	2,566	724
Other assets	(280)	(316)
Other liabilities	1,736	1,540
Net cash flows from operating activities	20,737	16,160
Cash flows from investing activities:
Purchases of fixed maturity securities	(5,246)	(6,684)
Purchases of equity securities	(7,818)	(6,454)
Purchases of other investments	(12,250)
Sales of fixed maturity securities	2,137	2,607
Redemptions and maturities of fixed maturity securities	4,739	4,646
Sales of equity securities	2,938	7,006
Purchases of loans and finance receivables	(446)	(546)
Collections of loans and finance receivables	565	1,098
Acquisitions of businesses, net of cash acquired	(830)	(1,831)
Purchases of property, plant and equipment	(7,727)	(7,193)
Other	(1,526)	(115)
Net cash flows from investing activities	(25,464)	(7,466)
Cash flows from financing activities:
Change in short-term borrowings, net	(1,269)	(989)
Acquisitions of noncontrolling interests and other	(3,064)	(76)
Net cash flows from financing activities	(213)	1,679
Effects of foreign currency exchange rate changes	27	104
Increase (decrease) in cash and cash equivalents	(4,913)	10,477
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	46,992	37,299
Cash and cash equivalents at end of first nine months	42,079	47,776
Insurance and Other [Member]
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(2,529)	(720)
Depreciation	1,497	1,443
Cash flows from financing activities:
Proceeds from borrowings	2,608	1,796
Repayments of borrowings	(2,811)	(1,962)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	42,358	33,513
Cash and cash equivalents at end of first nine months	35,337	41,820
Railroad, Utilities and Energy [Member]
Adjustments to reconcile net earnings to operating cash flows:
Depreciation	2,403	2,235
Cash flows from financing activities:
Proceeds from borrowings	5,496	4,699
Repayments of borrowings	(836)	(1,137)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,570	2,246
Cash and cash equivalents at end of first nine months	4,691	4,119
Finance and Financial Products [Member]
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(182)	(216)
Cash flows from financing activities:
Proceeds from borrowings	2,506	2,357
Repayments of borrowings	(2,843)	(3,009)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,064	1,540
Cash and cash equivalents at end of first nine months	$ 2,051	$ 1,837