Note 2 - Recently Issued Accounting Standards (Details Textual) - 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	Jan. 01, 2019
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total	$ 69,286	$ 67,420	$ 76,616	$ 50,532	$ 51,798	$ 89,680	$ 51,894	$ 36,360	$ 263,854	$ 229,732	$ 151,781
Liabilities, Total	1,425,077				1,373,005				1,425,077	1,373,005
Assets, Total	3,001,077				2,780,292				3,001,077	2,780,292
Cumulative Effect of New Accounting Principle in Period of Adoption					1,774					1,774
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption					5,766					5,766
Homebuilding Segment [Member]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total									217,494	185,939	$ 115,378
Liabilities, Total	1,249,719				1,207,564				1,249,719	1,207,564
Assets, Total	$ 2,748,202				$ 2,558,086				2,748,202	$ 2,558,086
Accounting Standards Update 2016-01 [Member]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total									$ (1,600)
Accounting Standards Update 2016-02 [Member] | Subsequent Event [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption												$ (100)
Accounting Standards Update 2016-02 [Member] | Subsequent Event [Member] | Homebuilding Segment [Member]
Liabilities, Total												33,600
Operating Lease, Liability, Total												34,300
Assets, Total												33,500
Operating Lease, Right-of-Use Asset												$ 33,200