Note 12 - Related Party Transactions (Details Textual) - USD ($)		1 Months Ended	3 Months Ended			12 Months Ended				48 Months Ended
	Oct. 23, 2017	Aug. 31, 2017	Sep. 30, 2019	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2015	Jun. 26, 2019	Jun. 30, 2019	Jun. 30, 2018
Due from Affiliates						$ 238,000	$ 1,218,000
Equity Method Investments						30,217,000	34,330,000
Revenue from Contract with Customer, Including Assessed Tax						669,349,000	667,566,000	$ 751,166,000
Cost of Goods and Services Sold, Total						616,207,000	605,666,000	660,240,000
Income (Loss) from Equity Method Investments, Total						(3,503,000)	(19,653,000)	866,000
Payments to Acquire Interest in Joint Venture						8,826,000	15,066,000	27,479,000
Proceeds from (Repayments of) Notes Payable, Total						0	0	(4,110,000)
Equity Method Investment, Acquisition of Partner Interest		$ 2,600,000
Tidelands [Member]
Income (Loss) from Equity Method Investments, Total								200,000	$ 1,600,000
Deferred Revenue, Equity Method Investments									$ 400,000
Deferred Revenue, Equity Method Investments, Write Off				$ 100,000
Payments to Acquire Interest in Joint Venture	$ 13,600,000			13,600,000
Proceeds from (Repayments of) Notes Payable, Total	$ (4,100,000)			$ (4,100,000)
Larkspur [Member]
Income (Loss) from Equity Method Investments, Total					$ 100,000
Equity Method Investment, Gain (Loss) on Difference Between Carrying Amount and Underlying Equity					300,000
Interest Income on Note to Joint Venture [Member] | Encore McKinley [Member]
Debt Instrument, Interest Rate, Stated Percentage												10.00%
Interest Income, Related Party							100,000	500,000
Corporate Joint Venture [Member] | Construction-related Costs [Member]
Related Party Transaction, Expenses from Transactions with Related Party						5,500,000	6,400,000	7,300,000
Due from Affiliates						200,000	400,000
Corporate Joint Venture [Member] | Management Fees [Member]
Due from Affiliates						0	200,000
Revenue from Related Parties						$ 1,900,000	3,400,000	4,900,000
Related Party [Member]
Common Stock Beneficial Ownership Percentage, Significant Amount Threshold						10.00%
TNHC Merdian Investors LLC, and TNHC Russel Ranch LLC [Member]
Equity Method Investments						$ 13,700,000	6,500,000
Arantine Hills Holdings LP, Calabasas Village LP, and TNHC-TCN Santa Clarita, LP [Member]
Equity Method Investments						8,200,000	12,000,000.0
Joint Venture Agreement, Contribution Over Cap			$ 2,800,000		$ 4,000,000.0
IHP [Member] | LLC Agreement of Russell Ranch [Member]
Joint Venture Agreement, Additional Required Capital Agreed to Fund											$ 26,000,000
Joint Venture Agreement, Additional Required Capital Agreed to Fund, Percentage Funded by Related Party											50.00%
Joint Venture Agreement, Additional Required Capital Agreed to Fund, Percentage Funded by Entity											50.00%
Director [Member] | Russel Ranch [Member]
Deposit Assets, Total								5,100,000
Purchase Options, Land								34,000,000.0
TL Fab LP [Member] | Trade Payment [Member]
Related Party Transaction, Amounts of Transaction						200,000	300,000	600,000
Accounts Payable, Related Parties						0	7,000
TL Fab LP [Member] | Trade Payment [Member] | Unconsolidated Joint Ventures [Member]
Related Party Transaction, Amounts of Transaction						0	400,000	900,000
Accounts Payable, Related Parties						0	8,000
Joint Venture Land Sales [Member]
Deferred Profit From Lot Transactions						0	200,000
TNHC-HW Cannery LLC [Member]
Due from Affiliates						15,000	37,000
Related Party Transaction, Payments for Profit Participation						0	0
Related Party Transaction, Profit Participation, Refund								200,000
Related Party Transaction, Profit Participation Due						0	0
Land Owner Fees Reimbursed						100,000	100,000	0
Consultant Davis [Member]
Due from Affiliates						0	600,000
Consultant Davis [Member] | Fee Building Revenue [Member]
Revenue from Contract with Customer, Including Assessed Tax						500,000	3,000,000.0	500,000
Cost of Goods and Services Sold, Total						500,000	2,900,000	500,000
Consultant Davis [Member] | General Contractor [Member]
Revenue from Contract with Customer, Including Assessed Tax						15,000	83,000	13,000
Consultant Davis [Member] | Monthly Consulting Fee [Member]
Related Party Transaction, Amounts of Transaction			1,000							$ 5,000
Accounts Payable, Related Parties						0	0
Consultant Stelmar [Member] | Monthly Consulting Fee [Member]
Related Party Transaction, Amounts of Transaction						48,000	90,000	$ 175,000
Accounts Payable, Related Parties						0
Consultant Redwitz [Member] | Monthly Consulting Fee [Member]
Related Party Transaction, Amounts of Transaction						10,000
Accounts Payable, Related Parties						0
10% Common Stock Affiliate [Member] | Northern CA Phased Takedown [Member]
Purchase Options, Land						16,100,000
Master Marketing Fees						400,000
10% Common Stock Affiliate [Member] | Northern CA Rolling Option [Member]
Deposit Assets, Total						0
Land Owner Fees Reimbursed						200,000
Estimated Purchase Price						$ 56,300,000
Percentage of Lots Agreed to Be Purchased by Unrelated Third Party						67.00%
Number of Lots Remaining to Purchase From Affiliate						0
Option Payment						$ 3,000,000.0
Amounts Paid for Purchase of Lots						18,000,000.0
10% Common Stock Affiliate [Member] | Northern CA Finished Lots [Member]
Purchase Options, Land						8,000,000.0
Master Marketing Fees						300,000
Reimbursed Costs						200,000
10% Common Stock Affiliate [Member] | Arizona Master Plan [Member]
Purchase Options, Land						3,800,000
Deposits Assets						300,000
Bedford [Member]
Purchase Options, Land						10,000,000.0
Deposits Assets						1,500,000
Board Affiliate [Member] | Bedford [Member]
Purchase Options, Land			$ 9,300,000
Master Marketing Fees						100,000
Board Affiliate [Member] | Bedford 2 [Member]
Purchase Options, Land							10,500,000
Master Marketing Fees						$ 200,000
Deposits Assets							1,400,000
Percentage of Optioned Lots Taken Down						92.00%
Deposit Assets Outstanding						$ 0
Fidelity [Member] | Payments for Record Keeping and Investment Management Services [Member]
Defined Contribution Plan, Record Keeping and Investment Management Services Paid by the Company							14,000
Defined Contribution Plan, Record Keeping and Investment Management Services Paid by the Participants							$ 6,000