Fair Value of Financial Assets and Liabilities (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value Disclosures [Abstract]

Composition of Investments

The following tables summarize the composition of our short- and long-term investments at September 30, 2012 and December 31, 2011 (tables in thousands):

	September 30, 2012
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Aggregate Fair Value
U.S. government and agency obligations	$	2,033,500	$	11,321	$	(1,005	)	$	2,043,816
U.S. corporate debt securities	1,360,511		12,772		(97		)	1,373,186
High yield corporate debt securities	468,285		31,408		(1,076		)	498,617
Asset-backed securities	3,227		8		—			3,235
Municipal obligations	1,023,504		4,379		(366		)	1,027,517
Auction rate securities	80,706		—		(5,860		)	74,846
Foreign debt securities	1,243,175		10,013		(198		)	1,252,990
Total fixed income securities	6,212,908		69,901		(8,602		)	6,274,207
Publicly traded equity securities	47,786		97,815		(625		)	144,976
Total	$	6,260,694	$	167,716	$	(9,227	)	$	6,419,183

	December 31, 2011
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Aggregate Fair Value
U.S. government and agency obligations	$	2,474,029	$	12,420	$	(1,488	)	$	2,484,961
U.S. corporate debt securities	1,400,373		9,953		(2,573		)	1,407,753
High yield corporate debt securities	442,723		12,498		(7,742		)	447,479
Asset-backed securities	29,101		72		(25		)	29,148
Municipal obligations	814,657		2,021		(597		)	816,081
Auction rate securities	82,900		—		(8,304		)	74,596
Foreign debt securities	984,696		5,185		(2,807		)	987,074
Total fixed income securities	6,228,479		42,149		(23,536		)	6,247,092
Publicly traded equity securities	58,199		6,802		—			65,001
Total	$	6,286,678	$	48,951	$	(23,536	)	$	6,312,093

Fair Value Hierarchy For Financial Assets And Liabilities Measured At Fair Value

The following table represents our fair value hierarchy for our financial assets and liabilities measured at fair value as of September 30, 2012 (in thousands):

	Level 1		Level 2			Level 3		Total
Cash	$	1,441,347	$	—		$	—	$	1,441,347
Cash equivalents	2,715,470		4,000			—		2,719,470
U.S. government and agency obligations	1,128,224		915,592			—		2,043,816
U.S. corporate debt securities	—		1,373,186			—		1,373,186
High yield corporate debt securities	—		498,617			—		498,617
Asset-backed securities	—		3,235			—		3,235
Municipal obligations	—		1,027,517			—		1,027,517
Auction rate securities	—		—			74,846		74,846
Foreign debt securities	—		1,252,990			—		1,252,990
Publicly traded equity securities	144,976		—			—		144,976
Total cash and investments	$	5,430,017	$	5,075,137		$	74,846	$	10,580,000
Other items:
Strategic investments held at cost	$	—	$	—		$	254,338	$	254,338
Convertible debt	—		(2,938,101		)	—		(2,938,101		)
Foreign exchange derivative assets	—		47,311			—		47,311
Foreign exchange derivative liabilities	—		(23,426		)	—		(23,426		)
Commodity derivative liabilities	—		(1,502		)	—		(1,502		)

Changes in Fair Value of Level 3 Financial Assets

The following table provides a summary of changes in fair value of our Level 3 auction rate securities for the three and nine months ended September 30, 2012 (table in thousands):

	For the Three Months Ended					For the Nine Months Ended
	September 30, 2012		September 30, 2011			September 30, 2012			September 30, 2011
Balance, beginning of the period	$	73,896	$	99,154		$	74,596		$	146,044
Calls at par value	—		(13,100		)	(225		)	(64,600		)
Other-than-temporary impairment loss	—		—			(1,969		)	—
(Increase) decrease in previously recognized unrealized losses included in other comprehensive income	950		(4,963		)	2,444			(353		)
Balance, end of the period	$	74,846	$	81,091		$	74,846		$	81,091

Unrealized Losses on Investments by Investment Category and Length of Time in Continuous Unrealized Loss Position

Unrealized losses on investments at September 30, 2012 by investment category and length of time the investment has been in a continuous unrealized loss position are as follows (table in thousands):

	Less Than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency obligations	$	247,834	$	(906	)	$	9,186	$	(99	)	$	257,020	$	(1,005	)
U.S. corporate debt securities	96,205		(91		)	2,234		(6		)	98,439		(97		)
High yield corporate debt securities	30,208		(697		)	1,354		(379		)	31,562		(1,076		)
Municipal obligations	192,338		(362		)	2,614		(4		)	194,952		(366		)
Auction rate securities	—		—			74,846		(5,860		)	74,846		(5,860		)
Foreign debt securities	98,849		(198		)	—		—			98,849		(198		)
Publicly traded equity securities	1,097		(625		)	—		—			1,097		(625		)
Total	$	666,531	$	(2,879	)	$	90,234	$	(6,348	)	$	756,765	$	(9,227	)

Contractual Maturities of Investments

The contractual maturities of fixed income securities held at September 30, 2012 are as follows (table in thousands):

	September 30, 2012
	Amortized Cost Basis		Aggregate Fair Value
Due within one year	$	1,271,478	$	1,275,151
Due after 1 year through 5 years	4,083,712		4,118,038
Due after 5 years through 10 years	463,518		488,630
Due after 10 years	394,200		392,388
Total	$	6,212,908	$	6,274,207