XML 31 R20.htm IDEA: XBRL DOCUMENT v3.8.0.1
Marketable Securities (Tables)
 9 Months Ended
Oct. 31, 2017
Investments Debt And Equity Securities [Abstract]  
Amortized Cost, Gross Unrealized Gains (Losses) and Fair Value of Available-For-Sale Securities

The amortized cost, gross unrealized gains (losses) and fair value of available-for-sale securities by major security type and class of security as of October 31, 2017, January 31, 2017 and October 31, 2016 were as follows:

 

 

 

Amortized

 

 

Unrealized

 

 

Unrealized

 

 

Fair

 

 

 

Cost

 

 

Gains

 

 

(Losses)

 

 

Value

 

As of October 31, 2017

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Short-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

$

67,275

 

 

$

2

 

 

$

(71

)

 

$

67,206

 

Municipal and pre-refunded municipal bonds

 

 

24,676

 

 

 

4

 

 

 

(14

)

 

 

24,666

 

Certificates of deposit

 

 

1,356

 

 

 

—

 

 

 

—

 

 

 

1,356

 

 

 

 

93,307

 

 

 

6

 

 

 

(85

)

 

 

93,228

 

Long-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

 

30,051

 

 

 

2

 

 

 

(87

)

 

 

29,966

 

Municipal and pre-refunded municipal bonds

 

 

1,362

 

 

 

—

 

 

 

(2

)

 

 

1,360

 

Mutual funds, held in rabbi trust

 

 

5,639

 

 

 

109

 

 

 

(2

)

 

 

5,746

 

Certificates of deposit

 

 

4,182

 

 

 

—

 

 

 

—

 

 

 

4,182

 

 

 

 

41,234

 

 

 

111

 

 

 

(91

)

 

 

41,254

 

 

 

$

134,541

 

 

$

117

 

 

$

(176

)

 

$

134,482

 

As of January 31, 2017

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Short-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

$

59,403

 

 

$

7

 

 

$

(90

)

 

$

59,320

 

Municipal and pre-refunded municipal bonds

 

 

51,731

 

 

 

28

 

 

 

(12

)

 

 

51,747

 

 

 

 

111,134

 

 

 

35

 

 

 

(102

)

 

 

111,067

 

Long-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

 

19,102

 

 

 

9

 

 

 

(33

)

 

 

19,078

 

Municipal and pre-refunded municipal bonds

 

 

19,488

 

 

 

35

 

 

 

(9

)

 

 

19,514

 

Mutual funds, held in rabbi trust

 

 

4,583

 

 

 

91

 

 

 

(1

)

 

 

4,673

 

Certificates of deposit

 

 

1,023

 

 

 

—

 

 

 

—

 

 

 

1,023

 

 

 

 

44,196

 

 

 

135

 

 

 

(43

)

 

 

44,288

 

 

 

$

155,330

 

 

$

170

 

 

$

(145

)

 

$

155,355

 

As of October 31, 2016

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Short-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

$

17,809

 

 

$

1

 

 

$

(19

)

 

$

17,791

 

Municipal and pre-refunded municipal bonds

 

 

6,859

 

 

 

—

 

 

 

(6

)

 

 

6,853

 

 

 

 

24,668

 

 

 

1

 

 

 

(25

)

 

 

24,644

 

Long-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

 

222

 

 

 

1

 

 

 

—

 

 

 

223

 

Municipal and pre-refunded municipal bonds

 

 

307

 

 

 

—

 

 

 

—

 

 

 

307

 

Mutual funds, held in rabbi trust

 

 

4,544

 

 

 

—

 

 

 

(97

)

 

 

4,447

 

Certificates of deposit

 

 

628

 

 

 

—

 

 

 

—

 

 

 

628

 

 

 

 

5,701

 

 

 

1

 

 

 

(97

)

 

 

5,605

 

 

 

$

30,369

 

 

$

2

 

 

$

(122

)

 

$

30,249