Business Segments Business Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenue	$ 4,504,670	$ 4,033,502	$ 4,131,393
Land and Housing	3,305,781	3,014,573	3,087,551
General and administrative	258,422	222,765	214,811
Selling	234,373	208,942	191,580
Operating income (loss):	706,094	587,222	637,451
Interest Expense			2,250
Interest Income, net of Interest Expense	(27,514)	(20,022)	(2,250)
Other Income	0	(33)	(6)
Income before income taxes	733,608	607,277	635,207
Depreciation and amortization:	17,386	15,791	17,174
Northern Homebuilding [Member]
Segment Reporting Information [Line Items]
Revenue	1,900,013	1,523,943	1,714,236
Land and Housing	1,480,326	1,228,949	1,379,936
General and administrative	42,908	36,827	36,659
Selling	95,680	81,847	80,142
Operating income (loss):	281,099	176,320	217,499
Interest Income, net of Interest Expense	(228)	(186)	(469)
Depreciation and amortization:	3,787	3,673	3,308
Southern Homebuilding [Member]
Segment Reporting Information [Line Items]
Revenue	2,488,451	2,415,730	2,330,962
Land and Housing	1,825,455	1,785,624	1,707,615
General and administrative	76,200	65,078	61,775
Selling	136,198	124,860	109,698
Operating income (loss):	450,598	440,168	451,874
Interest Income, net of Interest Expense	(2,554)	(1,703)	(1,447)
Depreciation and amortization:	3,636	2,965	2,790
Financial Service
Segment Reporting Information [Line Items]
Revenue	116,206	93,829	86,195
Land and Housing	0	0	0
General and administrative	52,826	45,115	41,813
Selling	0	0	0
Operating income (loss):	63,380	48,714	44,382
Interest Expense	13,698	10,360	5,122
Depreciation and amortization:	1,130	810	2,178
Operating Segments
Segment Reporting Information [Line Items]
General and administrative	171,934	147,020	140,247
Selling	231,878	206,707	189,840
Operating income (loss):	795,077	665,202	713,755
Interest Income, net of Interest Expense	(10,916)	(8,471)	(3,206)
Depreciation and amortization:	8,553	7,448	8,276
Corporate and Other [Member]
Segment Reporting Information [Line Items]
General and administrative	86,488	75,745	74,564
Selling	2,495	2,235	1,740
Less: Corporate selling, general and administrative expenses	(88,983)	(77,980)	(76,304)
Interest and Other Income	(38,430)	(28,493)	(956)
Depreciation and amortization:	$ 8,833	$ 8,343	$ 8,898