Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Homebuilding
Total revenues									$ 11,036,082	$ 10,212,957	$ 10,188,331
Income before income taxes	$ 481,151	$ 420,103	$ 396,585	$ 244,218	$ 402,407	$ 333,862	$ 295,698	$ 204,294	1,542,057	1,236,261	1,288,804
Financial Services:
Income before income taxes	42,599	64,064	60,424	19,551	33,544	32,284	25,078	12,409	186,637	103,315
Consolidated results:
Consolidated revenues	3,192,363	2,954,957	2,593,781	2,294,980	3,016,913	2,710,365	2,488,985	1,996,693
Income before income taxes	523,750	484,167	457,009	263,769	435,951	366,146	320,776	216,703	1,728,694	1,339,576	1,347,540
Income tax expense	(85,639)	(67,769)	(108,389)	(60,058)	(100,153)	(93,042)	(79,735)	(49,946)	(321,855)	(322,876)	(325,517)
Net income	$ 438,111	$ 416,398	$ 348,620	$ 203,711	$ 335,798	$ 273,104	$ 241,041	$ 166,757	$ 1,406,839	$ 1,016,700	$ 1,022,023
Net income per share:
Basic (usd per share)	$ 1.62	$ 1.54	$ 1.29	$ 0.75	$ 1.23	$ 0.99	$ 0.86	$ 0.59	$ 5.19	$ 3.67	$ 3.56
Diluted (usd per share)	$ 1.62	$ 1.54	$ 1.29	$ 0.74	$ 1.22	$ 0.99	$ 0.86	$ 0.59	$ 5.18	$ 3.66	$ 3.55
Number of shares used in calculation:
Basic shares outstanding (shares)	267,561	268,363	268,324	270,000	270,843	272,992	276,652	277,637	268,553	274,495	283,578
Effect of dilutive securities (shares)	666	598	701	1,218	632	640	932	1,003	861	802	1,287
Diluted shares outstanding (shares)	268,227	268,961	269,025	271,218	271,475	273,632	277,584	278,640	269,414	275,297	284,865
Financial Service [Member]
Homebuilding
Total revenues	$ 105,945	$ 106,871	$ 94,802	$ 54,550	$ 69,797	$ 64,815	$ 55,957	$ 43,862	$ 362,169	$ 234,431	$ 205,382
Cost of Revenue									175,481	130,770	147,422
Total Homebuilding [Member]
Homebuilding
Total revenues	3,086,418	2,848,086	2,498,979	2,240,430	2,947,116	2,645,550	2,433,028	1,952,831	10,673,913	9,978,526	9,982,949
Cost of Revenue	$ 2,320,077	$ 2,152,243	$ 1,900,250	$ 1,709,879	$ 2,279,615	$ 2,035,972	$ 1,874,369	$ 1,494,841	$ 8,082,449	$ 7,684,798	$ 7,667,497