Basket Limitation

No definition available.

Name:	nwhm_BasketLimitation
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Balance Type:	na
Period Type:	instant

- Definition

Percent of Debt Instrument Par Value Issued

+ References

No definition available.

+ Details

Name:	nwhm_PercentofDebtInstrumentParValueIssued
Namespace Prefix:	nwhm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

+ Details

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

- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

+ Details

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

- Definition

Amount, after accumulated amortization, of debt premium.

+ References

+ Details

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

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-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 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Details

Name:	nwhm_OtherNotesPayableAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nwhm_A2012NotesPayabletoLandSellerMember
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Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
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Data Type:	na
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Period Type:

- Details

Name:	nwhm_AccordionFeatureCreditFacilityAxis=nwhm_AccordionFeatureMaximumBorrowingCapacityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nwhm_SeniorNoteAxis=nwhm_NetCashProceedsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nwhm_SeniorNoteAxis=nwhm_SrNotesDue2022Member
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nwhm_SeniorNoteAxis=nwhm_SrNotesDue2022TackonMember
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- Details

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Balance Type:
Period Type:

- Details

Name:	nwhm_SeniorNoteAxis=nwhm_InvestmentsinJointVenturesandOtherInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nwhm_SeniorNoteAxis=nwhm_GeneralBasketMember
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Notes Payable - Additional Disclosures (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	May 04, 2017 USD ($)	Mar. 17, 2017 USD ($)	Dec. 19, 2016 USD ($)
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount	$ 2,200
Debt Instrument, Unamortized Premium	1,800
Debt Instrument, Unamortized Debt Issuance Costs	$ 5,900
Interest rate	7.25%
Long-term Debt	$ 318,656	$ 118,000
Gain (Loss) on Extinguishment of Debt	$ 0	250	$ 0
Notes Payable with Land Sellers [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 4,000						$ 3,750
Notes Payable with Land Sellers [Member] \| 2012 Notes Payable to Land Seller [Member]
Debt Instrument [Line Items]
Interest rate		7.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest rate at period end	4.56%
Maximum borrowing capacity	$ 260,000			$ 200,000	$ 260,000
Revolving Credit Facility [Member] \| Minimum [Member] \| Unsecured revolving credit facility \| LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Revolving Credit Facility [Member] \| Maximum [Member] \| Unsecured revolving credit facility \| LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Accordion Feature Maximum Borrowing Capacity [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 300,000	$ 350,000
Net Cash Proceeds [Member]
Debt Instrument [Line Items]
Basket Limitation	1.00
Sr Notes Due 2022 [Member]
Debt Instrument [Line Items]
Face value of note							$ 250,000
Percent of Debt Instrument Par Value Issued							98.96%
Interest rate at period end							7.50%
Sr Notes Due 2022 Tack-on [Member]
Debt Instrument [Line Items]
Face value of note						$ 75,000
Percent of Debt Instrument Par Value Issued						102.75%
Interest rate at period end						6.44%
Consolidated Net Income [Member]
Debt Instrument [Line Items]
Basket Limitation	0.50
Investments in Joint Ventures and Other Investments [Member]
Debt Instrument [Line Items]
Basket Limitation	0.15
General Basket [Member]
Debt Instrument [Line Items]
Basket Limitation	15,000,000