Note 24 - Supplemental Guarantor Information - Supplemental Condensed Combining Statements of Operations and Comprehensive Income (Details) - USD ($)	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 881,875,000	$ 785,638,000	$ 770,980,000	$ 626,723,000	$ 724,114,000	$ 603,751,000	$ 668,044,000	$ 581,705,000					$ 3,065,216,000	$ 2,577,614,000	$ 2,326,844,000
Inventory impairments	(10,002,000)	(11,098,000)	(200,000)	(550,000)	(620,000)	(4,540,000)		(4,850,000)	$ (3,873,000)	$ (4,700,000)	$ (1,600,000)		(21,850,000)	(10,010,000)	(10,173,000)
Selling, general, and administrative expenses	(93,366,000)	(83,523,000)	(81,571,000)	(71,341,000)	(81,379,000)	(69,102,000)	(70,709,000)	(66,298,000)
Net realized gains (losses) from the sales of marketable securities														18,122,000	1,074,000
Pretax income (loss)													263,854,000	229,732,000	151,781,000
Provision for income taxes													(53,074,000)	(87,897,000)	(48,570,000)
Net income	$ 54,725,000	$ 53,392,000	$ 63,899,000	$ 38,764,000	$ 24,552,000	$ 61,163,000	$ 33,871,000	$ 22,249,000					210,780,000	141,835,000	103,211,000
Other comprehensive income related to available-for-sale securities, net of tax														(18,079,000)	6,356,000
Comprehensive income													210,780,000	123,756,000	109,567,000
Other-than-temporary impairment of marketable securities														(286,000)	(1,443,000)
Provision for income taxes													(53,074,000)	(87,897,000)	(48,570,000)
Other-than-temporary impairment of marketable securities													0	(300,000)	(1,400,000)
Homebuilding Segment [Member]
Revenues													2,981,811,000	2,503,242,000	2,262,853,000
Cost of Sales													(2,415,139,000)	(2,078,273,000)	(1,889,257,000)
Inventory impairments													(21,850,000)	(10,010,000)	(10,173,000)
Gross margin													544,822,000	414,959,000	363,423,000
Selling, general, and administrative expenses													(329,801,000)	(287,488,000)	(250,540,000)
Equity income of subsidiaries
Interest and other income													7,718,000	7,714,000	6,033,000
Net realized gains (losses) from the sales of marketable securities														17,775,000	979,000
Realized gain from the sale of metropolitan district bond securities (related party)														35,847,000
Other expense													(5,245,000)	(2,817,000)	(3,447,000)
Pretax income (loss)													217,494,000	185,939,000	115,378,000
Other-than-temporary impairment of marketable securities														(51,000)
Other-than-temporary impairment of marketable securities														(51,000)	(1,070,000)
Financial Services Segment [Member]
Revenues													83,405,000	74,372,000	63,991,000
Net realized gains (losses) from the sales of marketable securities													(3,745,000)
Pretax income (loss)													46,360,000	43,793,000	36,403,000
Other-than-temporary impairment of marketable securities														(235,000)	(373,000)
Reportable Legal Entities [Member] | Parent Company [Member]
Pretax income (loss)													197,772,000	150,950,000	89,966,000
Provision for income taxes													13,008,000	(9,115,000)	13,245,000
Net income													210,780,000	141,835,000	103,211,000
Other comprehensive income related to available-for-sale securities, net of tax														(18,079,000)	6,356,000
Comprehensive income													210,780,000	123,756,000	109,567,000
Provision for income taxes													13,008,000	(9,115,000)	13,245,000
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Pretax income (loss)													276,101,000	180,427,000	151,917,000
Provision for income taxes													(55,539,000)	(64,051,000)	(48,613,000)
Net income													220,562,000	116,376,000	103,304,000
Other comprehensive income related to available-for-sale securities, net of tax
Comprehensive income													220,562,000	116,376,000	103,304,000
Provision for income taxes													(55,539,000)	(64,051,000)	(48,613,000)
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Pretax income (loss)													44,704,000	42,545,000	35,329,000
Provision for income taxes													(10,543,000)	(14,731,000)	(13,202,000)
Net income													34,161,000	27,814,000	22,127,000
Other comprehensive income related to available-for-sale securities, net of tax														3,382,000	1,084,000
Comprehensive income													34,161,000	31,196,000	23,211,000
Provision for income taxes													(10,543,000)	(14,731,000)	(13,202,000)
Reportable Legal Entities [Member] | Homebuilding Segment [Member] | Parent Company [Member]
Revenues
Cost of Sales
Inventory impairments
Gross margin
Selling, general, and administrative expenses													(64,824,000)	(52,252,000)	(39,632,000)
Equity income of subsidiaries													254,723,000	144,190,000	125,431,000
Interest and other income													7,843,000	5,420,000	4,257,000
Net realized gains (losses) from the sales of marketable securities														17,775,000	979,000
Realized gain from the sale of metropolitan district bond securities (related party)														35,847,000
Other expense													30,000	21,000	1,000
Pretax income (loss)													197,772,000	150,950,000	89,966,000
Other-than-temporary impairment of marketable securities														(51,000)
Other-than-temporary impairment of marketable securities															(1,070,000)
Reportable Legal Entities [Member] | Homebuilding Segment [Member] | Guarantor Subsidiaries [Member]
Revenues													2,981,811,000	2,503,242,000	2,262,853,000
Cost of Sales													(2,415,139,000)	(2,078,371,000)	(1,888,957,000)
Inventory impairments													(21,850,000)	(10,010,000)	(10,173,000)
Gross margin													544,822,000	414,861,000	363,723,000
Selling, general, and administrative expenses													(264,475,000)	(234,430,000)	(210,546,000)
Equity income of subsidiaries
Interest and other income													1,029,000	2,834,000	2,188,000
Net realized gains (losses) from the sales of marketable securities
Realized gain from the sale of metropolitan district bond securities (related party)
Other expense													(5,275,000)	(2,838,000)	(3,448,000)
Pretax income (loss)													276,101,000	180,427,000	151,917,000
Other-than-temporary impairment of marketable securities
Other-than-temporary impairment of marketable securities
Reportable Legal Entities [Member] | Homebuilding Segment [Member] | Non-Guarantor Subsidiaries [Member]
Revenues
Cost of Sales														98,000	(300,000)
Inventory impairments
Gross margin														98,000	(300,000)
Selling, general, and administrative expenses
Equity income of subsidiaries
Interest and other income													4,000	6,000	5,000
Net realized gains (losses) from the sales of marketable securities
Realized gain from the sale of metropolitan district bond securities (related party)
Other expense
Pretax income (loss)													4,000	104,000	(295,000)
Other-than-temporary impairment of marketable securities
Other-than-temporary impairment of marketable securities
Reportable Legal Entities [Member] | Financial Services Segment [Member] | Parent Company [Member]
Pretax income (loss)
Reportable Legal Entities [Member] | Financial Services Segment [Member] | Guarantor Subsidiaries [Member]
Pretax income (loss)
Reportable Legal Entities [Member] | Financial Services Segment [Member] | Non-Guarantor Subsidiaries [Member]
Pretax income (loss)													44,700,000	42,441,000	35,624,000
Consolidation, Eliminations [Member]
Pretax income (loss)													(254,723,000)	(144,190,000)	(125,431,000)
Provision for income taxes
Net income													(254,723,000)	(144,190,000)	(125,431,000)
Other comprehensive income related to available-for-sale securities, net of tax														(3,382,000)	(1,084,000)
Comprehensive income													(254,723,000)	(147,572,000)	(126,515,000)
Provision for income taxes
Consolidation, Eliminations [Member] | Homebuilding Segment [Member]
Revenues
Cost of Sales
Inventory impairments
Gross margin
Selling, general, and administrative expenses													(502,000)	(806,000)	(362,000)
Equity income of subsidiaries													(254,723,000)	(144,190,000)	(125,431,000)
Interest and other income													(1,158,000)	(546,000)	(417,000)
Net realized gains (losses) from the sales of marketable securities
Realized gain from the sale of metropolitan district bond securities (related party)
Other expense
Pretax income (loss)													(256,383,000)	(145,542,000)	(126,210,000)
Other-than-temporary impairment of marketable securities
Other-than-temporary impairment of marketable securities
Consolidation, Eliminations [Member] | Financial Services Segment [Member]
Pretax income (loss)													$ 1,660,000	$ 1,352,000	$ 779,000