Note 6 - Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ 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
Homebuilding: Net realized gains (losses) from the sales of marketable securities									$ (0)	$ (0)	$ 18,122
Homebuilding: Realized gain from the sale of metropolitan district bond securities (related party)									(0)	(0)	35,847
Other-than-temporary impairment of marketable securities									0	0	(300)
Income before income taxes	$ 112,246	$ 62,806	$ 74,331	$ 55,606	$ 69,286	$ 67,420	$ 76,616	$ 50,532	304,989	263,854	229,732
Provision for income taxes									(66,677)	(53,074)	(87,897)
Net income	$ 92,589	$ 50,580	$ 54,593	$ 40,550	$ 54,725	$ 53,392	$ 63,899	$ 38,764	238,312	210,780	141,835
Homebuilding Segment [Member]
Homebuilding: Net realized gains (losses) from the sales of marketable securities									0	0	17,775
Homebuilding: Realized gain from the sale of metropolitan district bond securities (related party)									0	0	35,847
Income before income taxes									244,762	217,494	185,939
Financial Services Segment [Member]
Homebuilding: Net realized gains (losses) from the sales of marketable securities									11,797	(3,745)	0
Interest and other income									17,223	1,155	3,955
Income before income taxes									60,227	46,360	43,793
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Income before income taxes									0	0	53,683
Provision for income taxes									0	0	(20,400)
Net income									0	0	33,283
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Homebuilding Segment [Member]
Homebuilding: Net realized gains (losses) from the sales of marketable securities									0	0	17,775
Homebuilding: Realized gain from the sale of metropolitan district bond securities (related party)									0	0	35,847
Other-than-temporary impairment of marketable securities									0	0	(51)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Financial Services Segment [Member]
Other-than-temporary impairment of marketable securities									0	0	(235)
Interest and other income									$ 0	$ 0	$ 347