3. Marketable Securities

During all periods shown, marketable securities are classified as available-for-sale. The amortized cost, gross unrealized gains (losses) and fair values of available-for-sale securities by major security type and class of security as of January 31, 2016 and 2015 are as follows:


	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		(Losses)			Value
As of January 31, 2016
Short-term Investments:
Corporate bonds	$	33,885	$	10	$	(25	)	$	33,870
Municipal and pre-refunded municipal bonds		26,243		33		—			26,276
Certificates of deposit		915		—		—			915

		61,043		43		(25	)		61,061

Long-term Investments:
Corporate bonds		12,227		9		(35	)		12,201
Municipal and pre-refunded municipal bonds		18,028		58		(2	)		18,084
Mutual funds, held in rabbi trust		4,604		6		(247	)		4,363
Certificates of deposit		1,952		—		—			1,952

		36,811		73		(284	)		36,600

	$	97,854	$	116	$	(309	)	$	97,661

As of January 31, 2015
Short-term Investments:
Corporate bonds	$	56,594	$	20	$	(24	)	$	56,590
Municipal and pre-refunded municipal bonds		30,509		41		(2	)		30,548
Certificates of deposit		11,127		5		—			11,132
Treasury bills		2,033		3		—			2,036
Commercial paper		3,938		2		—			3,940

		104,201		71		(26	)		104,246

Long-term Investments:
Corporate bonds		46,754		22		(40	)		46,736
Municipal and pre-refunded municipal bonds		42,840		113		(6	)		42,947
Mutual funds, held in rabbi trust		3,816		16		(54	)		3,778
Certificates of deposit		3,066		—		—			3,066
Treasury bills		7,111		9		—			7,120
Federal government agencies		799		2		—			801

		104,386		162		(100	)		104,448

	$	208,587	$	233	$	(126	)	$	208,694

Proceeds from the sales and maturities of available-for-sale securities were $374,057, $830,297 and $451,866 in fiscal 2016, 2015 and 2014, respectively. The Company included in “Interest income,” in the Consolidated Statements of Income, a net realized gain of $43 during fiscal 2016, a net realized gain of $237 during fiscal 2015 and a net realized loss of $101 during fiscal 2014. Amortization of discounts and premiums, net, resulted in a reduction of “Interest income” of $3,841, $6,696 and $10,932 for fiscal years 2016, 2015 and 2014, respectively. Mutual funds represent assets held in an irrevocable rabbi trust for the Company’s Non-qualified Deferred Compensation Plan (“NQDC”). These assets are a source of funds to match the funding obligations to participants in the NQDC but are subject to the Company’s general creditors. The Company elected the fair value option for financial assets for the mutual funds held in the rabbi trust resulting in all unrealized gains and losses being recorded in “Interest income” in the Consolidated Statements of Income.

The following tables show the gross unrealized losses and fair value of the Company’s marketable securities with unrealized losses that are not deemed to be other-than-temporarily impaired aggregated by the length of time that individual securities have been in a continuous unrealized loss position, at January 31, 2016 and January 31, 2015, respectively.


	January 31, 2016
	Less Than 12 Months					12 Months or Greater					Total
Description of Securities	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate bonds	$	30,745	$	(54	)	$	1,098	$	(6	)	$	31,843	$	(60	)
Municipal and pre-refunded municipal bonds		997		(2	)		434		—			1,431		(2	)
Mutual funds, held in rabbi trust		4,363		(247	)		—		—			4,363		(247	)

Total	$	36,105	$	(303	)	$	1,532	$	(6	)	$	37,637	$	(309	)


	January 31, 2015
	Less Than 12 Months					12 Months or Greater					Total
Description of Securities	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate bonds	$	55,384	$	(63	)	$	383	$	(1	)	$	55,767	$	(64	)
Municipal and pre-refunded municipal bonds		4,672		(8	)		—		—			4,672		(8	)
Mutual funds, held in rabbi trust		3,778		(54	)		—		—			3,778		(54	)
Certificates of deposit		1,600		—			—		—			1,600		—
Commercial paper		747		—			—		—			747		—

Total	$	66,181	$	(125	)	$	383	$	(1	)	$	66,564	$	(126	)

As of January 31, 2016 and 2015, there were a total of 84 and 172 securities with unrealized loss positions within the Company’s portfolio, respectively.