Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	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, 2018	Dec. 31, 2017	Dec. 31, 2016
Homebuilding
Revenue from Contract with Customer, Excluding Assessed Tax									$ 10,188,331	$ 8,577,686	$ 7,676,530
Income before income taxes	$ 324,938	$ 365,055	$ 388,453	$ 210,358	$ 385,508	$ 250,463	$ 103,599	$ 125,762	1,288,804	865,332	860,766
Financial Services:
Income before income taxes	4,553	19,633	20,717	13,833	23,259	17,786	18,948	13,503	58,736	73,496
Consolidated results:
Total revenues	2,999,150	2,649,366	2,569,722	1,970,093	2,794,890	2,131,058	2,021,859	1,629,878
Income before income taxes	329,491	384,688	409,170	224,191	408,767	268,249	122,547	139,265	1,347,540	938,828	933,850
Income tax expense	(91,842)	(95,153)	(85,081)	(53,440)	(331,352)	(90,710)	(21,798)	(47,747)	(325,517)	(491,607)	(331,147)
Net income	$ 237,649	$ 289,535	$ 324,089	$ 170,751	$ 77,415	$ 177,539	$ 100,749	$ 91,518	$ 1,022,023	$ 447,221	$ 602,703
Net income per share:
Basic (usd per share)	$ 0.84	$ 1.01	$ 1.12	$ 0.59	$ 0.26	$ 0.59	$ 0.32	$ 0.29	$ 3.56	$ 1.45	$ 1.76
Diluted (usd per share)	$ 0.84	$ 1.01	$ 1.12	$ 0.59	$ 0.26	$ 0.58	$ 0.32	$ 0.28	$ 3.55	$ 1.44	$ 1.75
Number of shares used in calculation:
Basic shares outstanding (shares)	278,964	283,489	285,276	286,683	292,174	298,538	312,315	317,756	283,578	305,089	339,747
Effect of dilutive securities (shares)	1,248	1,183	1,378	1,343	1,318	1,690	1,565	2,329	1,287	1,725	2,376
Diluted shares outstanding (shares)	280,212	284,672	286,654	288,026	293,492	300,228	313,880	320,085	284,865	306,814	342,123
Write-off of insurance receivables					$ 9,300	$ 5,300		$ 15,000
Financial Service [Member]
Homebuilding
Revenue from Contract with Customer, Excluding Assessed Tax	$ 55,059	$ 51,620	$ 52,764	$ 45,938	56,166	46,952	$ 47,275	41,767	$ 205,382	$ 192,160	$ 181,126
Cost of Revenue									147,422	119,289	108,573
Total Homebuilding [Member]
Homebuilding
Revenue from Contract with Customer, Excluding Assessed Tax	2,944,091	2,597,746	2,516,958	1,924,155	2,738,724	2,084,106	1,974,584	1,588,111	9,982,949	8,385,526	7,495,404
Cost of Revenue	$ 2,319,473	$ 1,976,220	$ 1,900,316	$ 1,471,488	$ 2,147,431	$ 1,589,728	$ 1,637,536	$ 1,220,906	$ 7,667,497	$ 6,595,601	$ 5,620,089