Note 18 - Supplemental Guarantor Information (Details Textual)	Dec. 31, 2019
Senior Notes [Member] \| Senior Notes Due 2022 [Member]
Debt Instrument, Conditions of Guarantee Release, Percentage of Tangible Assets Attributable to Immaterial Subsidiaries, Threshold for No Release	5.00%

With regard to the conditions for the release of a debt instrument, this element represents the threshold percentage of consolidated tangible assets attributable to all immaterial subsidiaries that are not guarantors, beyond which percentage no automatic and unconditional release and discharge of the guarantees of a guarantor shall occur.

No definition available.

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