Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

Name:	us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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)(3)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

+ Details

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

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

+ Details

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

- Definition

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.

+ References

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

+ Details

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

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=nbhc_OriginatedAndAcquiredLoansNotAccountedForUnderAccountingStandardCodificationThreeHundredTenThirtyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=nbhc_AccountingStandardCodificationThreeHundredTenToThirtyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReceivablesAcquiredWithDeterioratedCreditQualityAxis=us-gaap_ReceivablesAcquiredWithDeterioratedCreditQualityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

Allowance for Loan Losses - (Summary of Company's Allowance for Loan Losses ("All") and Recorded Investment in Loans) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 31,264	$ 29,174
Provision (recoupment) for loan losses	41	1,795
Ending balance	30,686	30,850
Carrying amount of loan investments			$ 3,702,334	$ 3,178,947	$ 2,953,655
Loans	31,264	29,174	30,686	31,264	30,850
Total Loans			3,702,334	3,178,947	2,953,655
Originated and acquired loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	31,193	28,949
Charge-offs	(716)	(210)
Recoveries	97	91
Provision (recoupment) for loan losses		1,800
Ending balance	30,574	30,630
Ending allowance balance individually evaluated for impairment			1,218		2,916
Ending allowance balance collectively evaluated for impairment			29,355		27,714
Loans individually evaluated for impairment			34,672		41,103
Loans collectively evaluated for impairment			3,555,353		2,772,488
Carrying amount of loan investments			3,590,025	3,058,324
Loans	31,193	28,949	30,574	31,193	30,630
Total Loans			3,590,025	3,058,324
ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	71	225
Provision (recoupment) for loan losses	41	(5)
Ending balance	112	220
Carrying amount of loan investments			112,309	120,623	140,064
Loans	71	225	112	71	220
Total Loans			112,309	120,623	140,064
ASC 310-30 [Member] \| Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Ending balance	113	220
Loans	113	220	113		220
Commercial Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	21,385	18,821
Ending balance	21,578	20,539
Carrying amount of loan investments			2,105,899		1,641,596
Loans	21,385	18,821	21,578	21,385	20,539
Total Loans			2,105,899		1,641,596
Commercial Portfolio Segment [Member] \| Originated and acquired loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	21,340	18,821
Charge-offs	(437)	(20)
Recoveries	42	11
Provision (recoupment) for loan losses	540	1,727
Ending balance	21,485	20,539
Ending allowance balance individually evaluated for impairment			1,185		2,866
Ending allowance balance collectively evaluated for impairment			20,300		17,673
Loans individually evaluated for impairment			24,175		31,946
Loans collectively evaluated for impairment			2,057,022		1,572,715
Loans	21,340	18,821	21,485	21,340	20,539
Commercial Portfolio Segment [Member] \| ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	45
Provision (recoupment) for loan losses	48
Ending balance	93
Carrying amount of loan investments			24,702		36,935
Loans	45		93	45
Total Loans			24,702		36,935
Commercial Portfolio Segment [Member] \| ASC 310-30 [Member] \| Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Ending balance	93
Loans	93		93
Residential Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,965	4,387
Ending balance	3,928	4,216
Carrying amount of loan investments			859,155		746,455
Loans	3,965	4,387	3,928	3,965	4,216
Total Loans			859,155		746,455
Residential Portfolio Segment [Member] \| Originated and acquired loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,965	4,387
Charge-offs		(8)
Recoveries	2	3
Provision (recoupment) for loan losses	(39)	(166)
Ending balance	3,928	4,216
Ending allowance balance individually evaluated for impairment			31		47
Ending allowance balance collectively evaluated for impairment			3,897		4,169
Loans individually evaluated for impairment			8,558		8,403
Loans collectively evaluated for impairment			838,597		722,582
Loans	3,965	4,387	3,928	3,965	4,216
Residential Portfolio Segment [Member] \| ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Carrying amount of loan investments			12,000		15,470
Total Loans			12,000		15,470
Consumer Loan [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	305	324
Ending balance	290	280
Carrying amount of loan investments			26,565		27,611
Loans	305	324	290	305	280
Total Loans			26,565		27,611
Consumer Loan [Member] \| Originated and acquired loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	305	319
Charge-offs	(279)	(182)
Recoveries	53	67
Provision (recoupment) for loan losses	211	72
Ending balance	290	276
Ending allowance balance individually evaluated for impairment					2
Ending allowance balance collectively evaluated for impairment			290		274
Loans individually evaluated for impairment			38		180
Loans collectively evaluated for impairment			26,197		26,614
Loans	305	319	290	305	276
Consumer Loan [Member] \| ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		5
Provision (recoupment) for loan losses		(1)
Ending balance		4
Carrying amount of loan investments			330		817
Loans		5			4
Total Loans			330		817
Consumer Loan [Member] \| ASC 310-30 [Member] \| Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Ending balance		4
Loans		4			4
Commercial Real Estate Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,609	5,642
Ending balance	4,890	5,815
Carrying amount of loan investments			710,715		537,993
Loans	5,609	5,642	4,890	5,609	5,815
Total Loans			710,715		537,993
Commercial Real Estate Portfolio Segment [Member] \| Originated and acquired loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,583	5,422
Recoveries		10
Provision (recoupment) for loan losses	(712)	167
Ending balance	4,871	5,599
Ending allowance balance individually evaluated for impairment			2		1
Ending allowance balance collectively evaluated for impairment			4,868		5,598
Loans individually evaluated for impairment			1,901		574
Loans collectively evaluated for impairment			633,537		450,577
Loans	5,583	5,422	4,871	5,583	5,599
Commercial Real Estate Portfolio Segment [Member] \| ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	26	220
Provision (recoupment) for loan losses	(7)	(4)
Ending balance	19	216
Carrying amount of loan investments			75,277		86,842
Loans	26	220	19	$ 26	216
Total Loans			75,277		86,842
Commercial Real Estate Portfolio Segment [Member] \| ASC 310-30 [Member] \| Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Ending balance	20	216
Loans	$ 20	$ 216	$ 20		$ 216