Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net earnings	$ 9,629	$ 6,597
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(997)	(19)
Depreciation	2,682	2,518
Other	450	428
Changes in operating assets and liabilities before business acquisitions:
Losses and loss adjustment expenses	583	(539)
Deferred charges reinsurance assumed	(309)	176
Unearned premiums	1,154	1,722
Receivables and originated loans	(180)	(1,565)
Derivative contract assets and liabilities	(1,543)	36
Income taxes	1,908	647
Other assets	(435)	(973)
Other liabilities	(31)	481
Net cash flows from operating activities	12,911	9,509
Cash flows from investing activities:
Purchases of fixed maturity securities	(4,083)	(4,605)
Purchases of equity securities	(6,052)	(5,277)
Purchases of other investments	(12,250)
Sales of fixed maturity securities	1,719	1,403
Redemptions and maturities of fixed maturity securities	3,827	3,268
Sales of equity securities	1,454	3,828
Purchases of loans and finance receivables	(326)	(471)
Collections of loans and finance receivables	330	425
Acquisitions of businesses, net of cash acquired	(154)	(469)
Purchases of property, plant and equipment	(4,758)	(4,579)
Other	(2,170)	(336)
Net cash flows from investing activities	(22,463)	(6,813)
Cash flows from financing activities:
Change in short-term borrowings, net	(973)	(912)
Acquisitions of noncontrolling interests and other	(3,076)	(19)
Net cash flows from financing activities	(1,705)	659
Effects of foreign currency exchange rate changes	(40)	7
Increase in cash and cash equivalents	(11,297)	3,362
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	46,992	37,299
Cash and cash equivalents at end of first six months	35,695	40,661
Insurance and Other [Member]
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(889)	5
Depreciation	994	955
Cash flows from financing activities:
Proceeds from borrowings	2,596	1,761
Repayments of borrowings	(2,775)	(1,915)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	42,358	33,513
Cash and cash equivalents at end of first six months	31,216	36,812
Railroad, Utilities and Energy [Member]
Adjustments to reconcile net earnings to operating cash flows:
Depreciation	1,597	1,476
Cash flows from financing activities:
Proceeds from borrowings	3,049	2,849
Repayments of borrowings	(311)	(524)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,570	2,246
Cash and cash equivalents at end of first six months	2,564	2,598
Finance and Financial Products [Member]
Adjustments to reconcile net earnings to operating cash flows:
Investment (gains) losses	(108)	(24)
Cash flows from financing activities:
Proceeds from borrowings	1,510	1,586
Repayments of borrowings	(1,725)	(2,167)
Cash and cash equivalents:
Cash and cash equivalents at beginning of year	2,064	1,540
Cash and cash equivalents at end of first six months	$ 1,915	$ 1,251