Name:	nick_IndirectFinanceReceivableNetOfUnearnedInterestAndDealerDiscount
Namespace Prefix:	nick_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Net amount of the investment after deducting the amount of unearned discounts (other than cash or quantity discounts and the like), finance charges, and interest included.

No definition available.

Name:	nick_NotesReceivableNetUnearnedInterest
Namespace Prefix:	nick_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents unearned discounts (other than cash or quantity discounts and the like) included in the net amount of indirect finance receivables, that are shown as a deduction from the related receivables.

No definition available.

Name:	nick_UnearnedDiscountIncludedInFinancingReceivables
Namespace Prefix:	nick_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents unearned interest included in the face amount of indirect finance receivables, that are shown as a deduction from the related receivables.

No definition available.

Name:	nick_UnearnedInterestInIndirectFinancingReceivables
Namespace Prefix:	nick_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524

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

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(3))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Subparagraph 3

-Article 9

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

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Article 5