Equity Method Investment, Impairment Of Joint Ventures

No definition available.

Name:	nwhm_EquityMethodInvestmentImpairmentOfJointVentures
Namespace Prefix:	nwhm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Equity Method Investments, Impairment of Unconsolidated Entity Investments

+ References

No definition available.

+ Details

Name:	nwhm_EquityMethodInvestmentsImpairmentofUnconsolidatedEntityInvestments
Namespace Prefix:	nwhm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Equity Method Investments, Number

+ References

No definition available.

+ Details

Name:	nwhm_EquityMethodInvestmentsNumber
Namespace Prefix:	nwhm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Equity method investment, acquisition of partner's interest

+ References

No definition available.

+ Details

Name:	nwhm_Equitymethodinvestmentacquisitionofpartnersinterest
Namespace Prefix:	nwhm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number Of Joint Venture Projects Impaired During Period

+ References

No definition available.

+ Details

Name:	nwhm_NumberOfJointVentureProjectsImpairedDuringPeriod
Namespace Prefix:	nwhm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Long-Term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. This does not include advances to clients.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04.2)
-URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e603758-122996

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6812-107765

+ Details

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

- Definition

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

+ 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

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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

- Definition

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 35
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=82895926&loc=d3e25351-111560

+ Details

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

- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(12))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(10))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 3: 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 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 5: 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(13)(f))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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

- Definition

Revenue, comprised of base and incentive revenue derived from the management of joint ventures, managing third-party properties, or another entity's operations.

+ References

+ Details

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

- Definition

Amount of cash inflow (outflow) from long-term debt supported by a written promise to pay an obligation.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromRepaymentsOfNotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=nwhm_GainonJointVentureCloseoutMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nwhm_RemeasurementAxis=nwhm_GainonFairValueRemeasurementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=nwhm_InterestIncomeonNotetoJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nwhm_HomebuildingJointVenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=nwhm_LandDevelopmentJointVenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Unconsolidated Joint Ventures - Additional Disclosures (Details)		1 Months Ended	3 Months Ended			12 Months Ended
	Oct. 23, 2017 USD ($)	Aug. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) project	Dec. 31, 2017 USD ($) project	Dec. 31, 2016 USD ($) project	Dec. 31, 2018 project	Dec. 31, 2018	Dec. 31, 2018 investment
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Impairment Of Joint Ventures						$ 28,776,000	$ 0	$ 0
Number Of Joint Venture Projects Impaired During Period \| project						1	0	0
Equity Method Investments, Impairment of Unconsolidated Entity Investments						$ 18,900,000	$ 0	$ 0
Other than Temporary Impairment Losses, Investments						1,100,000	$ 0	$ 0
Equity Method Investments, Number							10	13	10		10
Advances to Affiliate			$ 0			0	$ 3,800,000
Debt Instrument, Interest Rate, Stated Percentage										7.25%
Management fee revenue, unconsolidated joint ventures						3,385,000	4,945,000	$ 8,202,000
Equity method investment, acquisition of partner's interest	$ 13,600,000	$ 2,600,000			$ 20,600,000
Proceeds from (Repayments of) Notes Payable	$ 0						(4,110,000)	(15,636,000)
Equity in net income (loss) of unconsolidated joint ventures						(19,653,000)	866,000	7,691,000
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage										5.00%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage										35.00%
Gain on Joint Venture Closeout [Member] [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net income (loss) of unconsolidated joint ventures			300,000	$ 1,100,000
Gain on Fair Value Remeasurement [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net income (loss) of unconsolidated joint ventures			$ 100,000	$ 500,000
Interest Income on Note to Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage										10.00%
Homebuilding Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Impairment Of Joint Ventures							0
Land Development Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Impairment Of Joint Ventures						$ 28,776,000	$ 0	$ 0