Note 4 - Segment Reporting - Reconciliation of Revenue From Segments to Consolidated (Details) - USD ($) $ 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
Revenues	$ 1,104,468	$ 772,662	$ 751,441	$ 664,682	$ 881,875	$ 785,638	$ 770,980	$ 626,723	$ 3,293,253	$ 3,065,216	$ 2,577,614
Homebuilding Segment [Member]
Revenues									3,205,248	2,981,811	2,503,242
Homebuilding Segment [Member] | Reportable Segment, West [Member]
Revenues									1,771,060	1,567,141	1,316,069
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member]
Revenues									1,131,568	1,080,475	805,669
Homebuilding Segment [Member] | Reportable Segment, East [Member]
Revenues									302,620	334,195	381,504
Financial Services Segment [Member]
Revenues									88,005	83,405	74,372
Financial Services Segment [Member] | Mortgage Operations [Member]
Revenues									55,222	53,476	48,841
Financial Services Segment [Member] | Other Financial Services [Member]
Revenues									$ 32,783	$ 29,929	$ 25,531