XML 31 R20.htm IDEA: XBRL DOCUMENT v3.7.0.1
Marketable Securities (Tables)
 6 Months Ended
Jul. 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 July 31, 2017, January 31, 2017 and July 31, 2016 were as follows:

 

 

 

Amortized

 

 

Unrealized

 

 

Unrealized

 

 

Fair

 

 

 

Cost

 

 

Gains

 

 

(Losses)

 

 

Value

 

As of July 31, 2017

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Short-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

$

72,805

 

 

$

4

 

 

$

(61

)

 

$

72,748

 

Municipal and pre-refunded municipal bonds

 

 

36,630

 

 

 

15

 

 

 

(13

)

 

 

36,632

 

Certificates of deposit

 

 

815

 

 

 

—

 

 

 

—

 

 

 

815

 

 

 

 

110,250

 

 

 

19

 

 

 

(74

)

 

 

110,195

 

Long-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

 

14,906

 

 

 

—

 

 

 

(22

)

 

 

14,884

 

Municipal and pre-refunded municipal bonds

 

 

3,057

 

 

 

9

 

 

 

(2

)

 

 

3,064

 

Mutual funds, held in rabbi trust

 

 

5,183

 

 

 

103

 

 

 

—

 

 

 

5,286

 

Certificates of deposit

 

 

2,726

 

 

 

—

 

 

 

—

 

 

 

2,726

 

 

 

 

25,872

 

 

 

112

 

 

 

(24

)

 

 

25,960

 

 

 

$

136,122

 

 

$

131

 

 

$

(98

)

 

$

136,155

 

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 July 31, 2016

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Short-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

$

23,658

 

 

$

8

 

 

$

(24

)

 

$

23,642

 

Municipal and pre-refunded municipal bonds

 

 

34,720

 

 

 

43

 

 

 

(4

)

 

 

34,759

 

Certificates of deposit

 

 

830

 

 

 

—

 

 

 

—

 

 

 

830

 

 

 

 

59,208

 

 

 

51

 

 

 

(28

)

 

 

59,231

 

Long-term Investments:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corporate bonds

 

 

8,958

 

 

 

8

 

 

 

(9

)

 

 

8,957

 

Municipal and pre-refunded municipal bonds

 

 

12,191

 

 

 

29

 

 

 

(1

)

 

 

12,219

 

Mutual funds, held in rabbi trust

 

 

4,156

 

 

 

153

 

 

 

—

 

 

 

4,309

 

Certificates of deposit

 

 

515

 

 

 

—

 

 

 

—

 

 

 

515

 

 

 

 

25,820

 

 

 

190

 

 

 

(10

)

 

 

26,000

 

 

 

$

85,028

 

 

$

241

 

 

$

(38

)

 

$

85,231