Note 6 - Investments in and Advances to Unconsolidated Joint Ventures - Condensed Combined Financial Statements for Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents		$ 87,863	$ 41,874	$ 79,314
Restricted Cash, Total		424	116	117
Real estate inventories		398,973		433,938
Other assets		31,105		25,880
Total assets		579,936		603,189
Total liabilities		357,600		370,430
The New Home Company's equity(1)		222,224		232,647
Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance		112		112
Total equity		222,336	237,079	232,759	$ 240,030
Total liabilities and equity		579,936		603,189
Revenue from Contract with Customer, Including Assessed Tax		132,033	118,848
Cost of Goods and Services Sold, Total		120,366	105,837
Net income of unconsolidated joint ventures		(8,476)	(1,987)
Equity in net income (loss) of unconsolidated joint ventures reflected in the accompanying condensed consolidated statements of operations		(1,937)	184
Gross margin		11,667	13,011
Net income (loss)		(0)	(0)
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Cash and cash equivalents		30,514		31,484
Restricted Cash, Total		13,237		13,852
Real estate inventories		234,460		241,416
Other assets		4,108		3,843
Total assets		282,319		290,595
Accounts payable and accrued liabilities		16,570		16,778
Notes payable		21,910		28,665
Total liabilities		38,480		45,443
The New Home Company's equity(1)	[1]	28,403		27,722
Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance		215,436		217,430
Total equity		243,839		245,152
Total liabilities and equity		$ 282,319		$ 290,595
Debt-to-capitalization ratio		8.20%		10.50%
Debt-to-equity ratio		9.00%		11.70%
Revenue from Contract with Customer, Including Assessed Tax		$ 31,647	42,287
Cost of Goods and Services Sold, Total		30,285	41,774
Net income of unconsolidated joint ventures		1,362	513
Unconsolidated Joint Venture with More than 20 Percent Loss Allocation [Member]
Revenue from Contract with Customer, Including Assessed Tax		4,624	3,698
Cost of Goods and Services Sold, Total		3,065	3,375
Equity in net income (loss) of unconsolidated joint ventures reflected in the accompanying condensed consolidated statements of operations		(2,226)	(30)
Gross margin		1,559	323
Expenses		674	636
Net income (loss)		$ 885	$ (313)

[1] Balance represents the Company's interest, as reflected in the financial records of the respective joint ventures. This balance differs from the investment in and advances to unconsolidated joint ventures balance reflected in the Company's consolidated balance sheets by $0.8 million due an other-than-temporary impairment charge to the Company's investment, interest capitalized to the Company's investment in joint ventures and certain other differences in outside basis.