Marketable Securities, Available-for-sale (Tables)

6 Months Ended

Jun. 30, 2012

Marketable Securities, Available-for-sale

Fair value of the available-for-sale marketable securities, by type of security

								JUNE 30, 2012
(in thousands)	AMORTIZED COST		GROSS UNREALIZED GAINS		GROSS UNREALIZED LOSSES			ESTIMATED FAIR VALUE
Type of security:
U.S. Treasury securities	$	7,182	$	-	$	(7	)	$	7,175
Obligations of U.S. and local government agencies	140,646		700		(19		)	141,327
Corporate debt securities issued under
U.S. government/agency-backed programs	1,502		1		-			1,503
Corporate debt securities	76,568		102		(48		)	76,622
Asset-backed securities	37,570		72		(130		)	37,512
Total debt securities	263,468		875		(204		)	264,139
Time deposits	45,471		-		-			45,471
Short-term pooled investments	1,028		-		-			1,028
Total marketable securities, available-for-sale	$	309,967	$	875	$	(204	)	$	310,638
							DECEMBER 31, 2011
Type of security:
U.S. Treasury securities	$	1,557	$	-	$	(2	)	$	1,555
Obligations of U.S. and local government agencies	147,557		123		(860		)	146,820
Corporate debt securities issued under
U.S. government/agency-backed programs	1,453		3		-			1,456
Corporate debt securities	126,088		101		(523		)	125,666
Asset-backed securities	46,198		42		(496		)	45,744
Total debt securities	322,853		269		(1,881		)	321,241
Time deposits	25,500		-		-			25,500
Short-term pooled investments	275		-		-			275
Total marketable securities, available-for-sale	$	348,628	$	269	$	(1,881	)	$	347,016

Fair value of the available-for-sale marketable securities, by contractual maturity

(in thousands)	JUNE 30, 2012		DECEMBER 31, 2011
Contractual maturity:
Maturing in one year or less	$	72,766	$	167,413
Maturing after one year through three years	167,880		120,952
Maturing after three years	23,493		32,876
Total debt securities	264,139		321,241
Time deposits and short-term pooled investments	46,499		25,775
Total marketable securities, available-for-sale	$	310,638	$	347,016