Marketable Debt Securities

Investments in marketable debt securities were comprised of the following (in thousands):



	September 27, 2014
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Treasury securities	$	32,494	$	21	$	(3	)	$	32,512
Corporate bonds	32,996		4		(22		)	32,978
U.S. Agency bonds	19,568		8		(13		)	19,563
Municipal bonds	8,625		20		—			8,645
Commercial paper	4,996		—		(1		)	4,995
	$	98,679	$	53	$	(39	)	$	98,693



	December 28, 2013
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Treasury securities	$	23,975	$	15	$	(1	)	$	23,989
Corporate bonds	35,804		3		(23		)	35,784
U.S. Agency bonds	19,517		10		(4		)	19,523
Municipal bonds	7,474		23		(2		)	7,495
	$	86,770	$	51	$	(30	)	$	86,791

Maturities of marketable debt securities were as follows (in thousands):



	September 27, 2014				December 28, 2013
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Marketable debt securities – current (due in less than one year)	$	55,290	$	55,317	$	52,122	$	52,159
Marketable debt securities – non-current (due in one to two years)	43,389		43,376		34,648		34,632
	$	98,679	$	98,693	$	86,770	$	86,791

During the three months ended September 27, 2014 and September 28, 2013, $14.6 million and $8.5 million, respectively, of marketable debt securities matured and were redeemed at face value. During the nine months ended September 27, 2014 and September 28, 2013, $38.1 million and $31.8 million, respectively, of marketable debt securities matured and were redeemed at face value. During the nine months ended September 27, 2014, there were no other-than-temporary declines in market value.

Other Investments

During 2013, we made a minority equity investment in one of our strategic product-development partners. The carrying value of this investment at September 27, 2014 and December 28, 2013 using the cost method is $4.5 million and is included in other assets on our condensed consolidated balance sheets.