Amortization period over which outstanding balance of credit facility is paid off.

No definition available.

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

- Definition

Beneficial ownership limit percentage.

+ References

No definition available.

+ Details

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

- Definition

Commitment period for advances under Credit Facility.

+ References

No definition available.

+ Details

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

- Definition

Credit facility available as percentage of value of non-delinquent receivables.

+ References

No definition available.

+ Details

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

- Definition

Line of credit facility floor rate.

+ References

No definition available.

+ Details

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

- Definition

Minimum interest coverage ratio.

+ References

No definition available.

+ Details

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

- Definition

Percentage of borrowers obligation under credit agreement.

+ References

No definition available.

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ References

+ Details

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

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Average amount borrowed under the credit facility during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityAverageOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=nick_SeniorSecuredCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Credit Facility (Detail Textuals) - USD ($)					12 Months Ended
Credit Facility (Detail Textuals) - USD ($)	Mar. 29, 2019	Feb. 12, 2019	Nov. 08, 2017	Nov. 07, 2017	Mar. 31, 2019	Feb. 28, 2019	Jan. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Mar. 30, 2018
Line Of Credit Facility [Line Items]
Line of credit facility utilized					$ 145,000,000				$ 165,750,000
Interest coverage ratio description		The minimum interest coverage ratio to 0.44 to 1.0 for the measurement period ended on December 31, 2018, 0.20 to 1.0 for the measurement period ending January 31, 2019, and 1.0 to 1.0 for the measurement period ending February 28, 2019 and thereafter
Aggregate amount available under the line of credit		$ 140,000,000
Minimum interest coverage ratio						1.00%	0.20%	0.44%
Minimum
Line Of Credit Facility [Line Items]
Line of credit facility utilized					140,000,000				140,000,000
Maximum
Line Of Credit Facility [Line Items]
Line of credit facility utilized					$ 225,000,000				$ 225,000,000
Senior Secured Credit Facility
Line Of Credit Facility [Line Items]
Line of credit facility amount	$ 175,000,000
Debt instrument description of variable rate basis					Outstanding advances under the Credit Facility will accrue interest at a rate of LIBOR plus 3.75%
Debt Instrument, Basis Spread on Variable Rate	3.75%
Commitment period for advances under Credit Facility	3 years
Amortization period over which outstanding balance of credit facility is paid off	4 years
Senior Secured Credit Facility \| Maximum
Line Of Credit Facility [Line Items]
Credit Facility available as percentage of value of non-delinquent receivables	82.50%
Percentage of borrowers obligation under credit agreement	10.00%
Line of credit facility
Line Of Credit Facility [Line Items]
Line of credit facility amount										$ 200,000,000
Debt instrument description of variable rate basis			30-day LIBOR		30-day LIBOR
Debt Instrument, Basis Spread on Variable Rate			4.00%		4.00%
Maturity date			Mar. 31, 2018		Mar. 30, 2019
Line of credit facility, floor rate			1.00%		1.00%
Increased the beneficial ownership limit			30.00%	20.00%	30.00%