NOTE 4. INVESTMENTS

Our investments are classified as either available-for-sale or held-to-maturity. The following table summarizes available-for-sale and held-to-maturity investments as of March 31, 2017 and 2016 (in thousands):

	Available-for-Sale Investments
March 31, 2017	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Loss)			Fair Value
Corporate bonds	$	6,381	$	—	$	(4	)	$	6,377
Municipal bonds		678		—		(16	)		662
Total available-for-sale investments	$	7,059	$	—	$	(20	)	$	7,039

	Held-to-Maturity Investments
March 31, 2017	Amortized Cost		Gross Unrecognized Gain		Gross Unrecognized (Loss)			Fair Value
Certificates of deposit	$	3,735	$	1	$	(1	)	$	3,735
Commercial paper		5,588		—		(3	)		5,585
Corporate bonds		57,009		—		(186	)		56,823
Municipal bonds		361		—		(1	)		360
Total held-to-maturity investments	$	66,693	$	1	$	(191	)	$	66,503

	Available-for-Sale Investments
March 31, 2016	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Loss)			Fair Value
Corporate bonds	$	7,037	$	—	$	(12	)	$	7,025
Total available-for-sale investments	$	7,037	$	—	$	(12	)	$	7,025

	Held-to-Maturity Investments
March 31, 2016	Amortized Cost		Gross Unrecognized Gain		Gross Unrecognized (Loss)			Fair Value
Certificates of deposit	$	2,737	$	3	$	—		$	2,740
Commercial paper		12,455		—		(6	)		12,449
Corporate bonds		41,715		—		(117	)		41,598
Total held-to-maturity investments	$	56,907	$	3	$	(123	)	$	56,787

The amortized cost of our held-to-maturity investments approximates their fair value. As of March 31, 2017 and 2016, we did not have other-than-temporary impairment in the fair value of any individual security classified as held-to-maturity or available-for-sale. As of March 31, 2017 and 2016, we had unrealized losses on available-for-sale investments, net of related income taxes of $12,000 and $7,000, respectively. Redemptions of investments in accordance with the callable provisions during fiscal 2017, 2016 and 2015 were $0, $0 and $1.3 million, respectively.

The following table summarizes the amortized cost and fair value of our investments, classified by stated maturity as of March 31, 2017 and 2016 (in thousands):

	March 31, 2017				March 31, 2017
	Available-for-Sale Investments				Held-to-Maturity Investments
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in less than one year	$	6,381	$	6,377	$	45,184	$	45,124
Due in 1 to 3 years		678		662		21,509		21,379
Total investments	$	7,059	$	7,039	$	66,693	$	66,503

	March 31, 2016				March 31, 2016
	Available-for-Sale Investments				Held-to-Maturity Investments
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in less than one year	$	4,314	$	4,311	$	37,163	$	37,128
Due in 1 to 2 years		2,723		2,714		19,744		19,659
Total investments	$	7,037	$	7,025	$	56,907	$	56,787