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		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Cash and cash equivalents		$ 85,588	$ 48,224	$ 85,588	$ 48,224		$ 79,314
Restricted Cash, Total		144	124	144	124		117
Real estate inventories		370,949		370,949			433,938
Other assets		48,864		48,864			25,880
Total assets		541,594		541,594			603,189
Total liabilities		344,516		344,516			370,430
The New Home Company's equity(1)		196,966		196,966			232,647
Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance		112		112			112
Total equity		197,078	239,193	197,078	239,193	$ 222,336	232,759	$ 237,079	$ 240,030
Total liabilities and equity		541,594		541,594			603,189
Revenues		98,960	162,749	230,993	281,597
Cost of sales and expenses		106,211	145,295	226,577	251,132
Net income of unconsolidated joint ventures		(24,293)	1,591	(32,769)	(396)
Equity in net income (loss) of unconsolidated joint ventures reflected in the accompanying condensed consolidated statements of operations		(19,962)	185	(21,899)	369
Gross margin		(7,251)	17,454	4,416	30,465
Net income (loss)		(0)	19	(0)	19
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Cash and cash equivalents		28,375		28,375			31,484
Restricted Cash, Total		13,250		13,250			13,852
Real estate inventories		221,972		221,972			241,416
Other assets		3,778		3,778			3,843
Total assets		267,375		267,375			290,595
Accounts payable and accrued liabilities		11,100		11,100			16,778
Notes payable		11,633		11,633			28,665
Total liabilities		22,733		22,733			45,443
The New Home Company's equity(1)	[1]	28,465		28,465			27,722
Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance		216,177		216,177			217,430
Total equity		244,642		244,642			245,152
Total liabilities and equity		$ 267,375		$ 267,375			$ 290,595
Debt-to-capitalization ratio		4.50%		4.50%			10.50%
Debt-to-equity ratio		4.80%		4.80%			11.70%
Revenues		$ 30,290	59,078	$ 61,937	101,365
Cost of sales and expenses		28,672	57,288	58,957	99,062
Net income of unconsolidated joint ventures		1,618	1,790	2,980	2,303
Equity in net income (loss) of unconsolidated joint ventures reflected in the accompanying condensed consolidated statements of operations		(19,962)	185	(21,899)	369
Unconsolidated Joint Venture with More than 20 Percent Loss Allocation [Member]
Revenues		26,198	45,167	45,746	77,463
Cost of sales and expenses		24,012	41,352	41,314	70,686
Equity in net income (loss) of unconsolidated joint ventures reflected in the accompanying condensed consolidated statements of operations		(19,926)	247	(19,718)	486
Gross margin		2,186	3,815	4,432	6,777
Expenses		1,243	1,990	2,590	3,852
Net income (loss)		$ 943	$ 1,825	$ 1,842	$ 2,925

[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 $15.5 million due to other-than-temporary impairment charges to the Company's investment, interest capitalized to the Company's investment in joint ventures and certain other differences in outside basis.