Marketable Securities, Available-for-sale (Tables)

12 Months Ended

Dec. 31, 2014

Marketable Securities, Available-for-sale

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

	DECEMBER 31, 2014
(in thousands)		AMORTIZED COST		GROSS UNREALIZED GAINS		GROSS UNREALIZED LOSSES			ESTIMATED FAIR VALUE
Type of security:
U.S. Treasury securities	$	350	$	–	$	–		$	350
Municipal debt securities		13,529		1,715		(61	)		15,183
Total debt securities		13,879		1,715		(61	)		15,533
Time deposits		7,511		–		–			7,511
Total marketable securities, available-for-sale	$	21,390	$	1,715	$	(61	)	$	23,044

	DECEMBER 31, 2013
Type of security:
U.S. Treasury securities	$	76,355	$	149	$	–		$	76,504
Obligations of U.S. government agencies		17,074		2		(8	)		17,068
Municipal debt securities		33,492		492		(1,008	)		32,976
Corporate debt securities		157,798		102		(21	)		157,879
Asset-backed securities		20,433		76		(20	)		20,489
Total debt securities		305,152		821		(1,057	)		304,916
Time deposits		1,606		–		–			1,606
Short-term pooled investments		6,633		–		–			6,633
Total marketable securities, available-for-sale	$	313,391	$	821	$	(1,057	)	$	313,155

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

	DECEMBER 31,
(in thousands)		2014		2013
Contractual maturity:
Maturing in one year or less	$	350	$	129,384
Maturing after one year through three years		–		154,169
Maturing after three years		15,183		21,363
Total debt securities		15,533		304,916
Time deposits and short-term pooled investments		7,511		8,239
Total marketable securities, available-for-sale	$	23,044	$	313,155