Investments (Tables)

6 Months Ended

Oct. 28, 2017

Investments

Schedule of investments

Investments consist of the following (in thousands):

	October 28,		April 30,
	2017		2017
Short-term investments:
Held-to-maturity securities:
Municipal securities	$	43,901	$	47,437
U.S. government securities		22,609		14,515
Corporate bonds		44,241		55,519
Certificates of deposit		—		2,500
Total held-to-maturity and short-term investments	$	110,751	$	119,971
Long-term investments:
Held-to-maturity securities:
Municipal securities	$	3,898	$	8,942
U.S. government securities		25,021		22,540
Corporate bonds		2,009		8,117
Total held-to-maturity investments		30,928		39,599
Available-for-sale securities:
Auction rate securities		2,096		2,497
Total available-for-sale investments		2,096		2,497
Total long-term investments	$	33,024	$	42,096

Held-to-maturity securities

Investments

Schedule of amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of held-to-maturity investments

The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the held-to-maturity investments as of October 28, 2017 were as follows (in thousands):

	October 28, 2017
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Municipal securities	$	47,799	$	13	$	(16)	$	47,796
U.S. government securities		47,630		—		(115)		47,515
Corporate bonds		46,250		1		(43)		46,208
Certificates of deposit		—		—		—		—
Total held-to-maturity investments	$	141,679	$	14	$	(174)	$	141,519

The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the held-to-maturity investments as of April 30, 2017 were as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Municipal securities	$	56,379	$	30	$	(21)	$	56,388
U.S. government securities		37,055		2		(41)		37,016
Corporate bonds		63,636		9		(85)		63,560
Certificates of deposit		2,500		1		—		2,501
Total held-to-maturity investments	$	159,570	$	42	$	(147)	$	159,465

Schedule of amortized cost and fair value by contractual maturity

The amortized cost and fair value of the held-to-maturity securities by contractual maturity at October 28, 2017 were as follows (in thousands):

	Cost		Fair Value
Due within one year	$	110,751	$	110,660
Due after one year through five years		30,928		30,859
Total	$	141,679	$	141,519

Available-for-sale securities. | Auction rate securities

Investments

Schedule of amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of held-to-maturity investments

The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the auction rate securities as of October 28, 2017, were as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
Auction rate securities	$	2,250	$	—	$	(154)	$	2,096
Total available-for-sale investments	$	2,250	$	—	$	(154)	$	2,096

The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the auction rate securities as of April 30, 2017, were as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
Auction rate securities	$	2,700	$	—	$	(203)	$	2,497
Total available-for-sale investments	$	2,700	$	—	$	(203)	$	2,497

Schedule of amortized cost and fair value by contractual maturity

The amortized cost and fair value of the auction rate securities by contractual maturity at October 28, 2017, were as follows (in thousands):

	Cost		Fair Value
Due after one through five years	$	250	$	250
Due after 10 years		2,000		1,846
Total	$	2,250	$	2,096