XML 32 R21.htm IDEA: XBRL DOCUMENT
v3.20.2

Marketable Securities (Tables) | 3 Months Ended
--- | ---
Apr. 30, 2020
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 April 30, 2020, January 31, 2020 and April 30, 2019 were as follows:
|  | Amortized |  |  | Unrealized |  |  | Unrealized |  |  | Fair |
|  | Cost |  |  | Gains |  |  | (Losses) |  |  | Value |
As of April 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  | $ | 50,887 |  |  | $ | 5 |  |  | $ | (31 | ) |  | $ | 50,861 |
Corporate bonds |  |  | 14,246 |  |  |  | 21 |  |  |  | (7 | ) |  |  | 14,260 |
|  |  | 65,133 |  |  |  | 26 |  |  |  | (38 | ) |  |  | 65,121 |
Long-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  |  | 2,350 |  |  |  | 21 |  |  |  | (1 | ) |  |  | 2,370 |
Corporate bonds |  |  | 2,572 |  |  |  | 3 |  |  |  | (4 | ) |  |  | 2,571 |
Mutual funds, held in rabbi trust |  |  | 7,400 |  |  |  | 682 |  |  |  | — |  |  |  | 8,082 |
Certificates of deposit |  |  | 249 |  |  |  | — |  |  |  | — |  |  |  | 249 |
|  |  | 12,571 |  |  |  | 706 |  |  |  | (5 | ) |  |  | 13,272 |
|  | $ | 77,704 |  |  | $ | 732 |  |  | $ | (43 | ) |  | $ | 78,393 |
As of January 31, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  | $ | 38,617 |  |  | $ | 20 |  |  | $ | (11 | ) |  | $ | 38,626 |
Corporate bonds |  |  | 166,790 |  |  |  | 318 |  |  |  | (26 | ) |  |  | 167,082 |
Federal government agencies |  |  | 1,152 |  |  |  | 3 |  |  |  | — |  |  |  | 1,155 |
Certificates of deposit |  |  | 2,593 |  |  |  | — |  |  |  | — |  |  |  | 2,593 |
Commercial paper |  |  | 1,997 |  |  |  | — |  |  |  | — |  |  |  | 1,997 |
|  |  | 211,149 |  |  |  | 341 |  |  |  | (37 | ) |  |  | 211,453 |
Long-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  |  | 30,340 |  |  |  | 35 |  |  |  | (17 | ) |  |  | 30,358 |
Corporate bonds |  |  | 47,352 |  |  |  | 205 |  |  |  | (40 | ) |  |  | 47,517 |
Mutual funds, held in rabbi trust |  |  | 8,448 |  |  |  | 36 |  |  |  | (55 | ) |  |  | 8,429 |
Federal government agencies |  |  | 6,926 |  |  |  | 1 |  |  |  | (2 | ) |  |  | 6,925 |
Certificates of deposit |  |  | 3,867 |  |  |  | — |  |  |  | — |  |  |  | 3,867 |
|  |  | 96,933 |  |  |  | 277 |  |  |  | (114 | ) |  |  | 97,096 |
|  | $ | 308,082 |  |  | $ | 618 |  |  | $ | (151 | ) |  | $ | 308,549 |
|  | Amortized |  |  | Unrealized |  |  | Unrealized |  |  | Fair |
|  | Cost |  |  | Gains |  |  | (Losses) |  |  | Value |
As of April 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  | $ | 52,131 |  |  | $ | 23 |  |  | $ | (6 | ) |  | $ | 52,148 |
Corporate bonds |  |  | 169,627 |  |  |  | 72 |  |  |  | (70 | ) |  |  | 169,629 |
Federal government agencies |  |  | 2,735 |  |  |  | 4 |  |  |  | — |  |  |  | 2,739 |
Certificates of deposit |  |  | 1,650 |  |  |  | — |  |  |  | — |  |  |  | 1,650 |
Commercial paper |  |  | 2,997 |  |  |  | — |  |  |  | — |  |  |  | 2,997 |
|  |  | 229,140 |  |  |  | 99 |  |  |  | (76 | ) |  |  | 229,163 |
Long-term Investments: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Municipal and pre-refunded municipal bonds |  |  | 11,035 |  |  |  | 11 |  |  |  | (8 | ) |  |  | 11,038 |
Corporate bonds |  |  | 71,105 |  |  |  | 95 |  |  |  | (46 | ) |  |  | 71,154 |
Mutual funds, held in rabbi trust |  |  | 7,733 |  |  |  | 208 |  |  |  |  |  |  |  | 7,941 |
Federal government agencies |  |  | 2,351 |  |  |  | 7 |  |  |  | — |  |  |  | 2,358 |
Certificates of deposit |  |  | 1,403 |  |  |  | — |  |  |  | — |  |  |  | 1,403 |
|  |  | 93,627 |  |  |  | 321 |  |  |  | (54 | ) |  |  | 93,894 |
|  | $ | 322,767 |  |  | $ | 420 |  |  | $ | (130 | ) |  | $ | 323,057 |

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration