Note 23 - Results of Quarterly Operations (Unaudited) (Restated for Stock Dividends) - Results of Quarterly Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues	$ 1,104,468	$ 772,662	$ 751,441	$ 664,682	$ 881,875	$ 785,638	$ 770,980	$ 626,723	$ 3,293,253	$ 3,065,216	$ 2,577,614
Asset impairments	$ (325)	$ 0	$ 0	$ (610)	$ (10,002)	$ (11,098)	$ (200)	$ (550)
Gross margin from home sales (including impairments)	18.50%	18.80%	19.50%	18.90%	18.10%	17.70%	19.10%	18.20%
Homebuilding selling, general and administrative expenses	$ 105,101	$ 92,716	$ 82,712	$ 82,261	$ 93,366	$ 83,523	$ 81,571	$ 71,341
Pretax income	112,246	62,806	74,331	55,606	69,286	67,420	76,616	50,532	304,989	263,854	229,732
Net income	$ 92,589	$ 50,580	$ 54,593	$ 40,550	$ 54,725	$ 53,392	$ 63,899	$ 38,764	$ 238,312	$ 210,780	$ 141,835
Basic (in dollars per share)	$ 1.48	$ 0.81	$ 0.88	$ 0.66	$ 0.90	$ 0.87	$ 1.05	$ 0.64	$ 3.84	$ 3.46	$ 2.35
Diluted (in dollars per share)	$ 1.42	$ 0.79	$ 0.86	$ 0.64	$ 0.88	$ 0.86	$ 1.03	$ 0.63	$ 3.72	$ 3.39	$ 2.30
Home Building [Member]
Revenues	$ 1,074,852	$ 750,274	$ 732,844	$ 647,278	$ 858,488	$ 766,027	$ 749,608	$ 607,688