Finance Receivables (Detail Textuals) - USD ($)	3 Months Ended
Jun. 30, 2018	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables, net	$ 256,590,000	$ 269,876,000
Allowance for credit losses and provision expense	$ 151,000
Period for maintaining historical write off information with respect to static pool	10 years
Percentage of liquidation level assist in determining allowance for credit losses for 1st snapshot	20.00%
Percentage of liquidation level assist in determining allowance for credit losses for 2nd snapshot	40.00%
Percentage of liquidation level assist in determining allowance for credit losses for 3rd snapshot	60.00%
Percentage of liquidation level assist in determining allowance for credit losses in 4th snapshot	80.00%
Percentage of liquidation level assist in determining allowance for credit losses in 5th snapshot	100.00%
Finance receivables \| Direct Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of direct loan to total loan portfolio	2.00%
Finance receivables \| Direct Loans \| Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables, net	$ 1,000
Finance receivables \| Direct Loans \| Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables, net	$ 11,000

Represents information about allowance for credit losses and provision expense.

No definition available.

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Namespace Prefix:	nick_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This item represents the percentage of the direct loan in the total loan portfolio.

+ References

No definition available.

+ Details

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Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents Percentage of liquidation level assist in determining allowance for credit losses.

+ References

No definition available.

+ Details

Name:	nick_PercentageOfLiquidationLevelAssistInDeterminingAllowanceForCreditLosses
Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents Percentage of liquidation level assist in determining allowance for credit losses.

+ References

No definition available.

+ Details

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Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents Percentage of liquidation level assist in determining allowance for credit losses .

+ References

No definition available.

+ Details

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Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents Percentage of liquidation level assist in determining allowance for credit losses.

+ References

No definition available.

+ Details

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Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents Percentage of liquidation level assist in determining allowance for credit losses.

+ References

No definition available.

+ Details

Name:	nick_PercentageOfLiquidationLevelAssistInDeterminingAllowanceForCreditLossesTwo
Namespace Prefix:	nick_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period for maintaining historical write off information with respect to static pool.

+ References

No definition available.

+ Details

Name:	nick_PeriodForMaintainingHistoricalWriteOffInformationWithRespectToStaticPool
Namespace Prefix:	nick_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_NotesReceivableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_FinanceReceivablesMember
Namespace Prefix:
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
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- Details

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