XML 67 R60.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Stock Plans (Detail Textuals) - USD ($) $ in Millions | Aug. 31, 2019 | May 31, 2019
--- | --- | ---
Common Stock | New Stock Repurchase Program |  |
Equity Class Of Treasury Stock [Line Items] |  |
Stock repurchase program, authorized amount | $ 1.0 | $ 8.0

X
- Definition Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 505 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481520/505-30-50-4 + Details
Name: | srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | srt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_EquityClassOfTreasuryStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ShareRepurchaseProgramAxis=nick_NewStockRepurchaseProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |