Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	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, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Write-off of insurance receivables	-9297	-5326		-15000					29624
Homebuilding:
Revenues	$ 2,737,391	$ 2,083,067	$ 1,973,571	$ 1,587,061	$ 2,438,903	$ 1,894,885	$ 1,756,832	$ 1,396,730	$ 8,381,090	$ 7,487,350	$ 5,841,211
Cost of revenues	(2,147,431)	(1,589,728)	(1,637,536)	(1,220,906)	(1,835,928)	(1,429,133)	(1,314,972)	(1,040,056)	(6,595,601)	(5,620,089)	(4,271,803)
Income before income taxes	385,508	250,463	103,599	125,762	388,724	191,063	172,546	108,433	865,332	860,766	757,317
Financial Services:
Revenues	56,166	46,952	47,275	41,767	54,175	48,020	43,082	35,848	192,160	181,126	140,753
Income before income taxes	23,259	17,786	18,948	13,503	24,997	21,272	17,034	9,780	73,496	73,084
Consolidated results:
Total revenues	2,793,557	2,130,019	2,020,846	1,628,828	2,493,078	1,942,905	1,799,914	1,432,578	8,573,250	7,668,476	5,981,964
Income before income taxes	408,767	268,249	122,547	139,265	413,721	212,335	189,580	118,213	938,828	933,850	816,023
Income tax expense	(331,352)	(90,710)	(21,798)	(47,747)	(140,549)	(83,865)	(71,820)	(34,913)	(491,607)	(331,147)	(321,933)
Net income	$ 77,415	$ 177,539	$ 100,749	$ 91,518	$ 273,172	$ 128,470	$ 117,760	$ 83,300	$ 447,221	$ 602,703	$ 494,090
Net income per share:
Basic (usd per share)	$ 0.26	$ 0.59	$ 0.32	$ 0.29	$ 0.83	$ 0.37	$ 0.34	$ 0.24	$ 1.45	$ 1.76	$ 1.38
Diluted (usd per share)	$ 0.26	$ 0.58	$ 0.32	$ 0.28	$ 0.83	$ 0.37	$ 0.34	$ 0.24	$ 1.44	$ 1.75	$ 1.36
Number of shares used in calculation:
Basic shares outstanding (shares)	292,174	298,538	312,315	317,756	325,975	340,171	345,240	347,815	305,089	339,747	356,576
Effect of dilutive securities (shares)	1,318	1,690	1,565	2,329	1,834	2,250	2,759	2,662	1,725	2,376	3,217
Diluted shares outstanding (shares)	293,492	300,228	313,880	320,085	327,809	342,421	347,999	350,477	306,814	342,123	359,793