Note 4 - Segment Reporting - Reconciliation of Revenue From Segments to Consolidated (Details) - USD ($) $ 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
Revenues	$ 881,875	$ 785,638	$ 770,980	$ 626,723	$ 724,114	$ 603,751	$ 668,044	$ 581,705	$ 3,065,216	$ 2,577,614	$ 2,326,844
Homebuilding Segment [Member]
Revenues									2,981,811	2,503,242	2,262,853
Homebuilding Segment [Member] | Reportable Segment, West [Member]
Revenues									1,567,141	1,316,069	1,128,513
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member]
Revenues									1,080,475	805,669	756,997
Homebuilding Segment [Member] | Reportable Segment, East [Member]
Revenues									334,195	381,504	377,343
Financial Services Segment [Member]
Revenues									83,405	74,372	63,991
Financial Services Segment [Member] | Mortgage Operations [Member]
Revenues									53,476	48,841	41,585
Financial Services Segment [Member] | Other Financial Services [Member]
Revenues									$ 29,929	$ 25,531	$ 22,406