Fair value measurements (Tables)

12 Months Ended

Dec. 31, 2011

Fair values of financial assets and liabilities

The estimated fair values of our financial instruments are shown in the following table (in millions). The carrying values of cash and cash equivalents, accounts receivable and accounts payable, accruals and other liabilities are deemed to be reasonable estimates of their fair values.

	Carrying Value				Fair Value
	December 31,				December 31,
	2011		2010		2011		2010
Investments in fixed maturity securities	$	32,188	$	34,883	$	32,188	$	34,883
Investments in equity securities		76,991		61,513		76,991		61,513
Other investments		16,921		23,009		17,927		24,147
Loans and finance receivables		13,934		15,226		13,126		14,453
Derivative contract assets (1)		327		574		327		574
Notes payable and other borrowings:
Insurance and other		13,768		12,471		14,334		12,705
Railroad, utilities and energy		32,580		31,626		38,257		33,932
Finance and financial products		14,036		14,477		14,959		15,191
Derivative contract liabilities:
Railroad, utilities and energy (2)		336		621		336		621
Finance and financial products		10,139		8,371		10,139		8,371

⁽¹⁾ Included in other assets

⁽²⁾ Included in accounts payable, accruals and other liabilities

Financial assets and liabilities measured and carried at fair value on a recurring basis in the financial statements

Financial assets and liabilities measured and carried at fair value on a recurring basis in our financial statements are summarized, according to the hierarchy previously described, as follows (in millions).

	Total Fair Value			Quoted Prices (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
December 31, 2011
Investments in fixed maturity securities:
U.S. Treasury, U.S. government corporations and agencies	$	2,935		$	843	$	2,090		$	2
States, municipalities and political subdivisions		3,070			—		3,069			1
Foreign governments		10,843			4,444		6,265			134
Corporate bonds		12,448			—		11,801			647
Mortgage-backed securities		2,892			—		2,892			—
Investments in equity securities		76,991			76,906		63			22
Other investments		11,669			—		—			11,669
Net derivative contract (assets)/liabilities:
Railroad, utilities and energy		265			12		276			(23	)
Finance and financial products:
Equity index put options		8,499			—		—			8,499
Credit default obligations		1,472			—		—			1,472
Other		(88	)		—		(48	)		(40	)

	Total Fair Value		Quoted Prices (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
December 31, 2010
Investments in fixed maturity securities:
U.S. Treasury, U.S. government corporations and agencies	$	2,197	$	535	$	1,658	$	4
States, municipalities and political subdivisions		3,581		—		3,581		—
Foreign governments		11,912		5,633		6,167		112
Corporate bonds		14,054		23		13,346		685
Mortgage-backed securities		3,139		—		3,139		—
Investments in equity securities		61,513		61,390		88		35
Other investments		17,589		—		—		17,589
Net derivative contract (assets)/liabilities:
Railroad, utilities and energy		390		7		52		331
Finance and financial products:
Equity index put options		6,712		—		—		6,712
Credit default obligations		1,239		—		—		1,239
Other		77		—		137		(60	)

Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3)

Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) for each of the three years ending December 31, 2011 follow (in millions).

	Investments in fixed maturity securities			Investments in equity securities			Other investments			Net derivative contract liabilities
Balance at December 31, 2008	$	639		$	328		$	10,275		$	(14,519	)
Gains (losses) included in:
Earnings		1			4			—			3,635
Other comprehensive income		49			25			4,702			—
Regulatory assets and liabilities		—			—			—			47
Purchases, dispositions and settlements		244			(8	)		5,637			1,664
Transfers into (out of) Level 3		(15	)		(45	)		—			(23	)
Balance at December 31, 2009	$	918		$	304		$	20,614		$	(9,196	)
Gains (losses) included in:
Earnings		—			—			1,305			471
Other comprehensive income		16			(8	)		(358	)		—
Regulatory assets and liabilities		—			—			—			(33	)
Purchases, dispositions and settlements		9			(1	)		(3,972	)		533
Transfers into (out of) Level 3		(142	)		(260	)		—			3
Balance at December 31, 2010	$	801		$	35		$	17,589		$	(8,222	)
Gains (losses) included in:
Earnings		—			—			—			(2,035	)
Other comprehensive income		5			(13	)		(2,120	)		(3	)
Regulatory assets and liabilities		—			—			—			144
Purchases/Issuances		17			—			5,000			(68	)
Dispositions		(39	)		—			—			—
Settlements		—			—			—			275
Transfers into (out of) Level 3		—			—			(8,800	)		1
Balance at December 31, 2011	$	784		$	22		$	11,669		$	(9,908	)