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, 2015 and 2014 are as follows:


	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Fair Value
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
Certificates of deposit		3,066		—		—			3,066
Treasury bills		7,111		9		—			7,120
Mutual funds, held in rabbi trust		3,816		16		(54	)		3,778
Federal government agencies		799		2		—			801

		104,386		162		(100	)		104,448

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

As of January 31, 2014
Short-term Investments:
Corporate bonds	$	100,856	$	56	$	(41	)	$	100,871
Municipal and pre-refunded municipal bonds		85,000		98		(2	)		85,096
Certificates of deposit		35,844		13		(1	)		35,856
Treasury bills		24,873		10		—			24,883
Commercial paper		35,101		7		(1	)		35,107

		281,674		184		(45	)		281,813

Long-term Investments:
Corporate bonds		208,446		268		(162	)		208,552
Municipal and pre-refunded municipal bonds		125,934		415		(8	)		126,341
Certificates of deposit		4,000		—		(2	)		3,998
Treasury bills		21,551		21		—			21,572
Mutual funds, held in rabbi trust		1,591		108		(33	)		1,666
Federal government agencies		4,287		6		—			4,293

		365,809		818		(205	)		366,422

	$	647,483	$	1,002	$	(250	)	$	648,235

Proceeds from the sale and maturities of available-for-sale securities were $830,297, $451,866 and $207,576 in fiscal 2015, 2014 and 2013, respectively. The Company included in “Interest income,” in the Consolidated Statements of Income, a net realized gain of $237 during fiscal 2015, a net realized loss of $101 during fiscal 2014 and a net realized gain of $248 during fiscal 2013. Amortization of discounts and premiums, net, resulted in a reduction of “Interest income” of $6,696, $10,932 and $5,276 for fiscal years 2015, 2014 and 2013, 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 and not as a component of accumulated Other comprehensive (loss) 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, 2015 and January 31, 2014, respectively.


	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	)
Certificates of deposit		1,600		—			—		—			1,600		—
Treasury bills		—		—			—		—			—		—
Commercial paper		747		—			—		—			747		—
Mutual funds, held in rabbi trust		3,778		(54	)		—		—			3,778		(54	)
Federal government agencies		—		—			—		—			—		—

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


	January 31, 2014
	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	$	147,731	$	(203	)	$	—	$	—		$	147,731	$	(203	)
Municipal and pre-refunded municipal bonds		6,291		(10	)		—		—			6,291		(10	)
Certificates of deposit		12,746		(3	)		—		—			12,746		(3	)
Treasury bills		6,606		—			—		—			6,606		—
Commercial paper		6,640		(1	)		—		—			6,640		(1	)
Mutual funds, held in rabbi trust		1,666		(33	)		—		—			1,666		(33	)
Federal government agencies		1,753		—			—		—			1,753		—

Total	$	183,433	$	(250	)	$	—	$	—		$	183,433	$	(250	)

As of January 31, 2015 and 2014, there were a total of 172 and 219 securities with unrealized loss positions within the Company’s portfolio, respectively.