Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Revenue from Contract with Customer, Excluding Assessed Tax									$ 10,212,957	$ 10,188,331	$ 8,577,686
Income before income taxes	$ 402,407	$ 333,862	$ 295,698	$ 204,294	$ 324,938	$ 365,055	$ 388,453	$ 210,358	1,236,261	1,288,804	865,332
Financial Services:
Income before income taxes	33,544	32,284	25,078	12,409	4,553	19,633	20,717	13,833	103,315	58,736
Consolidated results:
Consolidated revenues	3,016,913	2,710,365	2,488,985	1,996,693	2,999,150	2,649,366	2,569,722	1,970,093
Income before income taxes	435,951	366,146	320,776	216,703	329,491	384,688	409,170	224,191	1,339,576	1,347,540	938,828
Income tax expense	(100,153)	(93,042)	(79,735)	(49,946)	(91,842)	(95,153)	(85,081)	(53,440)	(322,876)	(325,517)	(491,607)
Net income	$ 335,798	$ 273,104	$ 241,041	$ 166,757	$ 237,649	$ 289,535	$ 324,089	$ 170,751	$ 1,016,700	$ 1,022,023	$ 447,221
Net income per share:
Basic (usd per share)	$ 1.23	$ 0.99	$ 0.86	$ 0.59	$ 0.84	$ 1.01	$ 1.12	$ 0.59	$ 3.67	$ 3.56	$ 1.45
Diluted (usd per share)	$ 1.22	$ 0.99	$ 0.86	$ 0.59	$ 0.84	$ 1.01	$ 1.12	$ 0.59	$ 3.66	$ 3.55	$ 1.44
Number of shares used in calculation:
Basic shares outstanding (shares)	270,843	272,992	276,652	277,637	278,964	283,489	285,276	286,683	274,495	283,578	305,089
Effect of dilutive securities (shares)	632	640	932	1,003	1,248	1,183	1,378	1,343	802	1,287	1,725
Diluted shares outstanding (shares)	271,475	273,632	277,584	278,640	280,212	284,672	286,654	288,026	275,297	284,865	306,814
Financial Service [Member]
Homebuilding
Revenue from Contract with Customer, Excluding Assessed Tax	$ 69,797	$ 64,815	$ 55,957	$ 43,862	$ 55,059	$ 51,620	$ 52,764	$ 45,938	$ 234,431	$ 205,382	$ 192,160
Cost of Revenue									130,770	147,422	119,289
Total Homebuilding [Member]
Homebuilding
Revenue from Contract with Customer, Excluding Assessed Tax	2,947,116	2,645,550	2,433,028	1,952,831	2,944,091	2,597,746	2,516,958	1,924,155	9,978,526	9,982,949	8,385,526
Cost of Revenue	$ 2,279,615	$ 2,035,972	$ 1,874,369	$ 1,494,841	$ 2,319,473	$ 1,976,220	$ 1,900,316	$ 1,471,488	$ 7,684,798	$ 7,667,497	$ 6,595,601