Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net earnings	$ 10,746	$ 13,494	$ 8,441
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses and other-than-temporary impairment losses	(1,274)	(2,085)	2,837
Depreciation	4,683	4,279	3,127
Other	811	255	(149)
Changes in operating assets and liabilities before business acquisitions:
Losses and loss adjustment expenses	3,063	1,009	2,165
Deferred charges reinsurance assumed	(329)	147	(39)
Unearned premiums	852	110	(21)
Receivables and originated loans	(1,159)	(1,979)	697
Derivative contract assets and liabilities	1,881	(880)	(5,441)
Income taxes	1,493	2,348	2,035
Other assets	(1,601)	(1,070)	2,438
Other liabilities	1,310	2,267	(244)
Net cash flows from operating activities	20,476	17,895	15,846
Cash flows from investing activities:
Purchases of fixed maturity securities	(7,362)	(9,819)	(10,798)
Purchases of equity securities	(15,660)	(4,265)	(4,570)
Purchases of other investments	(5,000)		(7,068)
Sales of fixed maturity securities	3,353	5,435	4,338
Redemptions and maturities of fixed maturity securities	6,872	6,517	5,234
Sales of equity securities	1,518	5,886	5,626
Redemptions of other investments	12,645
Purchases of loans and finance receivables	(1,657)	(3,149)	(854)
Principal collections on loans and finance receivables	2,915	3,498	796
Acquisitions of businesses, net of cash acquired	(8,685)	(15,924)	(108)
Purchases of property, plant and equipment	(8,191)	(5,980)	(4,937)
Other	63	(476)	1,180
Net cash flows from investing activities	(19,189)	(18,277)	(11,161)
Cash flows from financing activities:
Changes in short term borrowings, net	301	370	(885)
Acquisitions of noncontrolling interests and other	(1,860)	(95)	(410)
Net cash flows from financing activities	(2,217)	8,125	233
Effects of foreign currency exchange rate changes	2	(74)	101
Increase (decrease) in cash and cash equivalents	(928)	7,669	5,019
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	38,227	30,558	25,539
Cash and cash equivalents at end of year	37,299	38,227	30,558
Insurance and Other [Member]
Cash flows from financing activities:
Proceeds from borrowings	2,091	8,204	289
Repayments of borrowings	(2,307)	(430)	(746)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	34,767	28,223
Cash and cash equivalents at end of year	33,513	34,767	28,223
Railroad, Utilities and Energy [Member]
Cash flows from financing activities:
Proceeds from borrowings	2,290	1,731	1,241
Repayments of borrowings	(2,335)	(777)	(444)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,557	429
Cash and cash equivalents at end of year	2,246	2,557	429
Finance and Financial Products [Member]
Cash flows from financing activities:
Proceeds from borrowings	1,562	1,539	1,584
Repayments of borrowings	(1,959)	(2,417)	(396)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	903	1,906
Cash and cash equivalents at end of year	$ 1,540	$ 903	$ 1,906