Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net earnings	$ 6,597	$ 5,145
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses and other-than-temporary impairment losses	(19)	(882)
Depreciation	2,518	2,276
Other	428	149
Changes in operating assets and liabilities before business acquisitions:
Losses and loss adjustment expenses	(539)	4,332
Deferred charges reinsurance assumed	176	(645)
Unearned premiums	1,722	1,580
Receivables and originated loans	(1,565)	(1,981)
Derivative contract assets and liabilities	36	(294)
Income taxes	647	599
Other assets	(973)	(1,607)
Other liabilities	481	1,311
Net cash flows from operating activities	9,509	9,983
Cash flows from investing activities:
Purchases of fixed maturity securities	(4,605)	(4,227)
Purchases of equity securities	(5,277)	(4,453)
Sales of fixed maturity securities	1,403	1,355
Redemptions and maturities of fixed maturity securities	3,268	3,518
Sales of equity securities	3,828	209
Redemptions of other investments		9,345
Purchases of loans and finance receivables	(471)	(1,511)
Principal collections on loans and finance receivables	425	2,494
Acquisitions of businesses, net of cash acquired	(469)	(172)
Purchases of property, plant and equipment	(4,579)	(3,444)
Other	(336)	79
Net cash flows from investing activities	(6,813)	3,193
Cash flows from financing activities:
Change in short term borrowings, net	(912)	(524)
Acquisitions of noncontrolling interests and other	(19)	(1,769)
Net cash flows from financing activities	659	(3,706)
Effects of foreign currency exchange rate changes	7	194
Increase in cash and cash equivalents	3,362	9,664
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	37,299	38,227
Cash and cash equivalents at end of first six months	40,661	47,891
Insurance and Other [Member]
Adjustments to reconcile net earnings to operating cash flows:
Depreciation	955	791
Cash flows from financing activities:
Proceeds from borrowings	1,761	51
Repayments of borrowings	(1,915)	(2,237)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	33,513	34,767
Cash and cash equivalents at end of first six months	36,812	43,193
Railroad, Utilities and Energy [Member]
Adjustments to reconcile net earnings to operating cash flows:
Depreciation	1,476	1,396
Cash flows from financing activities:
Proceeds from borrowings	2,849	1,540
Repayments of borrowings	(524)	(618)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,246	2,557
Cash and cash equivalents at end of first six months	2,598	2,804
Finance and Financial Products [Member]
Cash flows from financing activities:
Proceeds from borrowings	1,586	1,527
Repayments of borrowings	(2,167)	(1,676)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	1,540	903
Cash and cash equivalents at end of first six months	$ 1,251	$ 1,894