INVESTMENTS

The Company's investments are intended to establish a high-quality portfolio that preserves principal, meets liquidity needs, avoids inappropriate concentrations, and delivers an appropriate yield in relationship to the Company's investment guidelines and market conditions. The following is a summary of available-for-sale securities at March 31, 2016 (amounts in thousands):



	Available-for-sale Securities
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Government agency bonds	$	468,290	$	439	$	(99	)	$	468,630
Corporate bonds and debt	1,000		—		—			1,000
Marketable equity securities	2,195		8		—			2,203
Total	$	471,485	$	447	$	(99	)	$	471,833

The following is a summary of available-for-sale securities at March 31, 2015 (amounts in thousands):



	Available-for-sale Securities
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Government agency bonds	$	741,780	$	676	$	(200	)	$	742,256
Municipal bonds	41,552		155		(9		)	41,698
Auction rate securities	9,825		—		—			9,825
Time deposits ⁽¹⁾	506		—		—			506
Corporate bonds and debt	924,818		2,376		(265		)	926,929
Marketable equity securities	1,362		11,804		—			13,166
Total	$	1,719,843	$	15,011	$	(474	)	$	1,734,380

⁽¹⁾ Time deposits in various financial institutions with maturities greater than three months that will mature within one year.

At March 31, 2016, the Company's available-for-sale debt securities and marketable equity securities are presented on the consolidated balance sheets as short-term investments of $353.3 million and long-term investments of $118.5 million. At March 31, 2015, the Company’s available-for-sale debt securities and marketable equity securities are presented on the consolidated balance sheets as short-term investments of $1,351.1 million and long-term investments of $383.3 million.

The Company sold available-for-sale investments for proceeds of $1,501.5 million, $273.9 million and $135.3 million during the years ended March 31, 2016, 2015 and 2014, respectively. The Company sold available-for-sale investments during the fourth quarter of fiscal 2016 to finance a portion of the purchase price of its Atmel acquisition which closed on April 4, 2016. The Company had net realized gains of $13.7 million and $18.5 million from sales of available-for-sale marketable equity and debt securities during the years ended March 31, 2016 and 2015, respectively. The Company had no material realized gains or losses from the sale of available-for-sale equity and debt securities during the year ended March 31, 2014. The Company determines the cost of available-for-sale debt securities sold on a FIFO basis at the individual security level for sales from multiple lots. For sales of marketable equity securities, the Company uses an average cost basis at the individual security level. Gains and losses recognized in earnings are credited or charged to other income (expense) on the consolidated statements of income.

At March 31, 2016, the Company's marketable equity securities consisted of an investment in Adesto Technologies Corporation, which effected its initial public offering on the NASDAQ stock exchange on October 26, 2015. This investment was previously classified as available-for-sale corporate debt as of March 31, 2015. At March 31, 2015, the Company's marketable equity securities consisted of an investment in Hua Hong Semiconductor Limited (Hua Hong), which effected its initial public offering on the Hong Kong stock exchange on October 15, 2014. The Company sold all of its remaining shares of Hua Hong in the three months ended June 30, 2015.

The following tables show all investments in an unrealized loss position for which an other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position (amounts in thousands):



	March 31, 2016
	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Government agency bonds	$	148,562	$	(99	)	$	—	$	—	$	148,562	$	(99	)
Corporate bonds and debt	—		—			1,000		—		1,000		—
Total	$	148,562	$	(99	)	$	1,000	$	—	$	149,562	$	(99	)



	March 31, 2015
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Government agency bonds	$	162,948	$	(142	)	$	29,942	$	(58	)	$	192,890	$	(200	)
Municipal bonds	13,318		(9		)	—		—			13,318		(9		)
Corporate bonds and debt	163,095		(219		)	19,021		(46		)	182,116		(265		)
Total	$	339,361	$	(370	)	$	48,963	$	(104	)	$	388,324	$	(474	)

Management does not believe any of the unrealized losses represent an other-than-temporary impairment based on its evaluation of available evidence as of March 31, 2016 and the Company's intent is to hold these investments until these assets are no longer impaired. For those debt securities not scheduled to mature until after March 31, 2017, such recovery is not anticipated to occur in the next year and these investments have been classified as long-term investments on the consolidated balance sheet.

The amortized cost and estimated fair value of the available-for-sale securities at March 31, 2016, by contractual maturity, excluding marketable equity securities of $2.2 million, which have no contractual maturity, are shown below (amounts in thousands). Expected maturities can differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties, and the Company views its available-for-sale securities as available for current operations.



	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Available-for-sale
Due in one year or less	$	41,078	$	5	$	(5	)	$	41,078
Due after one year and through five years	428,212		434		(94		)	428,552
Due after five years and through ten years	—		—		—			—
Due after ten years	—		—		—			—
Total	$	469,290	$	439	$	(99	)	$	469,630

The amortized cost and estimated fair value of the available-for-sale securities at March 31, 2015, by maturity, excluding marketable equity securities of $13.2 million and corporate debt of $6.2 million, which have no contractual maturity, are shown below (amounts in thousands).



	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Available-for-sale
Due in one year or less	$	224,531	$	512	$	(34	)	$	225,009
Due after one year and through five years	1,395,685		2,648		(330		)	1,398,003
Due after five years and through ten years	82,250		47		(110		)	82,187
Due after ten years	9,825		—		—			9,825
Total	$	1,712,291	$	3,207	$	(474	)	$	1,715,024