Segment Information (Operating Data By Segment) (Details) - USD ($) $ 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
Segment Reporting Information
Total land-related charges									$ 191,912	$ 19,336	$ 11,467
Impairment Losses Related to Real Estate Partnerships			$ 8,000						8,017	0	0
Revenues:
Homebuilding	$ 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
Financial Services	56,166	46,952	47,275	41,767	54,175	48,020	43,082	35,848	192,160	181,126	140,753
Consolidated 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 (loss) before income taxes:
Consolidated income (loss) 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
Homebuilding	$ 385,508	$ 250,463	$ 103,599	$ 125,762	388,724	$ 191,063	$ 172,546	$ 108,433	$ 865,332	860,766	757,317
Charges related to contractual dispute										15,000	20,000
Write-off of insurance receivables	-9297	-5326		-15000					29624
Loss on debt retirements									$ 0	657	0
Adjustment to self insurance reserves	$ 75,300				$ 55,200				(95,100)	(55,200)	(62,200)
Reserves provided									(50)	506	(11,433)
Northeast [Member]
Segment Reporting Information
Total land-related charges									51,362	2,079	3,301
Revenues:
Homebuilding									693,624	696,463	682,112
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									21,190	81,991	82,616
Southeast [Member]
Segment Reporting Information
Total land-related charges									55,689	3,089	3,022
Revenues:
Homebuilding									1,563,322	1,491,270	1,058,089
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									122,532	145,011	172,330
Florida [Member]
Segment Reporting Information
Total land-related charges									9,702	715	4,555
Revenues:
Homebuilding									1,493,953	1,284,753	1,019,733
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									208,825	205,049	196,525
Product Warranty Expense									12,400
Texas [Member]
Segment Reporting Information
Total land-related charges									2,521	515	295
Revenues:
Homebuilding									1,167,750	1,034,673	845,772
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									182,862	152,355	121,329
Midwest [Member]
Segment Reporting Information
Total land-related charges									8,917	3,383	2,319
Revenues:
Homebuilding									1,449,466	1,234,650	1,020,691
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									178,231	120,159	91,745
West [Member]
Segment Reporting Information
Total land-related charges									56,995	8,960	(2,615)
Revenues:
Homebuilding									2,012,975	1,745,541	1,214,814
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									229,504	225,771	169,394
Other Homebuilding [Member]
Segment Reporting Information
Total land-related charges									6,726	595	590
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									(77,812)	(69,570)	(76,622)
Financial Services [Member]
Income (loss) before income taxes:
Consolidated income (loss) before income taxes									$ 73,496	73,084	58,706
Home Office Relocation [Member]
Income (loss) before income taxes:
Costs associated with the relocation of corporate headquarters										$ 8,300	$ 4,400