Available-for-sale investments (Tables)

6 Months Ended

Jun. 30, 2013

Investments, Debt and Equity Securities [Abstract]

Amortized cost, gross unrealized gains, gross unrealized losses and estimated fair values of available-for-sale investments by type of security

The amortized cost, gross unrealized gains, gross unrealized losses and estimated fair values of available-for-sale investments by type of security were as follows (in millions):

Type of security as of June 30, 2013	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
U.S. Treasury securities	$	4,800	$	—	$	(10	)	$	4,790
Other government-related debt securities:
U.S.	1,320		—		(14		)	1,306
Foreign and other	1,298		8		(41		)	1,265
Corporate debt securities:
Financial	3,919		30		(53		)	3,896
Industrial	4,052		27		(53		)	4,026
Other	413		3		(4		)	412
Residential mortgage-backed securities	1,477		4		(16		)	1,465
Other mortgage- and asset-backed securities	1,444		—		(37		)	1,407
Money market mutual funds	1,822		—		—			1,822
Other short-term interest-bearing securities	1,175		—		—			1,175
Total interest-bearing securities	21,720		72		(228		)	21,564
Equity securities	68		22		—			90
Total available-for-sale investments	$	21,788	$	94	$	(228	)	$	21,654

Type of security as of December 31, 2012	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
U.S. Treasury securities	$	4,443	$	15	$	—		$	4,458
Other government-related debt securities:
U.S.	1,018		12		—			1,030
Foreign and other	1,549		60		(1		)	1,608
Corporate debt securities:
Financial	3,266		96		(1		)	3,361
Industrial	4,283		100		(3		)	4,380
Other	441		11		—			452
Residential mortgage-backed securities	1,828		9		(8		)	1,829
Other mortgage- and asset-backed securities	1,769		7		(9		)	1,767
Money market mutual funds	2,620		—		—			2,620
Other short-term interest-bearing securities	2,186		—		—			2,186
Total interest-bearing securities	23,403		310		(22		)	23,691
Equity securities	52		2		—			54
Total available-for-sale investments	$	23,455	$	312	$	(22	)	$	23,745

Fair values of available-for-sale investments by classification in the Consolidated Balance Sheets

The fair values of available-for-sale investments by classification in the Condensed Consolidated Balance Sheets were as follows (in millions):

Classification in the Condensed Consolidated Balance Sheets	June 30, 2013		December 31, 2012
Cash and cash equivalents	$	5,352	$	2,887
Marketable securities	16,212		20,804
Other assets — noncurrent	90		54
Total available-for-sale investments	$	21,654	$	23,745

Fair values of available-for-sale interest-bearing security investments by contractual maturity

The fair values of available-for-sale interest-bearing security investments by contractual maturity, except for mortgage- and asset- backed securities that do not have a single maturity date, were as follows (in millions):

Contractual maturity	June 30, 2013		December 31, 2012
Maturing in one year or less	$	6,814	$	7,175
Maturing after one year through three years	4,500		5,014
Maturing after three years through five years	5,949		6,286
Maturing after five years through ten years	1,429		1,620
Mortgage- and asset-backed securities	2,872		3,596
Total interest-bearing securities	$	21,564	$	23,691