Note 13 - Per Share Calculations - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Net earnings (loss) attributable to Hovnanian	$ 46,178	$ (1,026)	$ (9,823)	$ (30,809)	$ 11,841	$ (337,209)	$ (6,682)	$ (143)	$ 4,520	$ (332,193)	$ (2,819)
Less: undistributed earnings allocated to nonvested shares									(159)
Numerator for basic earnings per share									4,361	(332,193)	(2,819)
Plus: undistributed earnings allocated to nonvested shares									159
Less: undistributed earnings reallocated to nonvested shares									(159)
Numerator for diluted earnings per share									$ 4,361	$ (332,193)	$ (2,819)
Denominator for basic earnings per share (in shares)	148,925	148,669	148,435	148,028	147,905	147,748	147,558	147,535	148,515	147,703	147,451
Share-based payments (in shares)									3,271
Denominator for diluted earnings per share – weighted-average shares outstanding (in shares)	151,929	148,669	148,435	148,028	160,548	147,748	147,558	147,535	151,786	147,703	147,451
Net income (loss) per common share (in dollars per share)	$ 0.30	$ (0.01)	$ (0.07)	$ (0.21)	$ 0.08	$ (2.28)	$ (0.05)	$ 0	$ 0.03	$ (2.25)	$ (0.02)
Diluted earnings (loss) per share (in dollars per share)	$ 0.29	$ (0.01)	$ (0.07)	$ (0.21)	$ 0.08	$ (2.28)	$ (0.05)	$ 0	$ 0.03	$ (2.25)	$ (0.02)