Note 6 - Investments in and Advances to Unconsolidated Joint Ventures - Condensed Combined Financial Statements for Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents		$ 107,279	$ 79,314	$ 42,273
Restricted Cash, Total		180	117	269
Real estate inventories		314,957	433,938
Other assets		50,703	25,880
Total assets		495,699	603,189
Total liabilities		298,257	370,430
The New Home Company's equity (1)		197,442	232,647
Other partners' equity		0	112
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance		197,442	232,759	240,030	$ 264,080
Total liabilities and equity		495,699	603,189
Revenues		507,411	669,349	667,566
Net loss of unconsolidated joint ventures		(32,869)	(8,001)	(14,230)
Equity in net loss of unconsolidated joint ventures reflected in the accompanying consolidated statements of operations		(18,791)	(3,503)	(19,653)
Inventory impairments		19,000	10,200	10,000
Gross margin		41,645	53,142	61,900
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Cash and cash equivalents		16,709	31,484
Restricted Cash, Total		611	13,852
Real estate inventories		3,172	241,416
Other assets		1,834	3,843
Total assets		22,326	290,595
Accounts payable and accrued liabilities		13,487	16,778
Notes payable		0	28,665
Total liabilities		13,487	45,443
The New Home Company's equity (1)	[1]	2,107	27,722
Other partners' equity		6,732	217,430
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance		8,839	245,152
Total liabilities and equity		$ 22,326	$ 290,595
Debt-to-capitalization ratio		0.00%	10.50%
Debt-to-equity ratio		0.00%	11.70%
Revenues		$ 137,819	$ 164,038	181,623
Cost of sales and expenses		161,772	230,953	209,527
Net loss of unconsolidated joint ventures		(23,953)	(66,915)	(27,904)
Equity in net loss of unconsolidated joint ventures reflected in the accompanying consolidated statements of operations		(18,791)	(3,503)	(19,653)
Unconsolidated Joint Venture with More than 20 Percent Loss Allocation [Member]
Revenues		55,517	33,144	38,789
Cost of sales and expenses		74,279	31,103	36,676
Equity in net loss of unconsolidated joint ventures reflected in the accompanying consolidated statements of operations	[2]	(17,744)	(3,656)	(20,283)
Inventory impairments		0	70,000	28,776
Gross margin		(18,762)	(67,959)	(26,663)
Expenses		(2,742)	(2,879)	(3,289)
Net loss		$ (21,504)	$ (70,838)	$ (29,952)

[1] Balance represents the Company's interest, as reflected in the financial records of the respective joint ventures. At December 31, 2019, this balance differs from the investment in and advances to unconsolidated joint ventures balance reflected in the Company's consolidated balance sheets by $2.5 million due to interest capitalized to the Company's investment in joint ventures and certain other differences in outside basis.

[2] Balance represents equity in net loss of unconsolidated joint ventures included in the statements of operations related to the Company's investment in these two unconsolidated joint ventures. The balance may differ from the amount of profit or loss allocated to the Company as reflected in each joint venture's financial records primarily due to basis differences such as other-than-temporary impairment charges, interest capitalized to the Company's investment in joint ventures, and/or profit deferral from lot sales from the joint ventures to the Company.