Note 20 - Supplemental Guarantor Information - Condensed Consolidating Statements of Cash Flows (Details) - USD ($)	1 Months Ended	6 Months Ended
	Apr. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Proceeds from the issuance of senior notes payable	$ 225,000,000	$ 579,125,000	$ 300,000,000
Payment of debt issuance costs		(4,595,000)	(2,195,000)
Loan from subsidiary
Net proceeds from (payments on) mortgage credit facility		(97,599,000)	(128,908,000)
(Contributions to) distributions from Corporate and subsidiaries
Repurchases of common stock		(150,014,000)	(99,829,000)
Common stock dividend payments		(9,019,000)	(9,527,000)
Issuance of common stock under employee stock plans, net of tax withholdings		(5,303,000)	1,069,000
Other financing activities		(67,000)	(199,000)
Intercompany advances, net
Net cash provided by (used in) financing activities		78,202,000	56,305,000
Net increase (decrease) in cash and equivalents		7,567,000	101,276,000
Cash and equivalents at beginning of period		208,127,000	186,594,000
Net cash provided by (used in) operating activities		592,000	63,614,000
Net cash provided by (used in) operating activities		592,000	63,614,000
Investments in unconsolidated homebuilding joint ventures		(25,002,000)	(22,592,000)
Distributions of capital from unconsolidated homebuilding joint ventures		8,045,000	8,115,000
Net cash paid for acquisitions		(44,477,000)
Loan to parent and subsidiaries
Other investing activities		(9,793,000)	(4,166,000)
Net cash provided by (used in) investing activities		(71,227,000)	(18,643,000)
Change in restricted cash		(3,711,000)	6,063,000
Borrowings from revolving credit facility		264,450,000	693,700,000
Principal payments on revolving credit facility		(264,450,000)	(693,700,000)
Principal payments on secured project debt and other notes payable		(615,000)	(10,169,000)
Principal payment on senior notes payable		(230,000,000)
Proceeds from Issuance of Senior Long-term Debt	$ 225,000,000	579,125,000	300,000,000
Payment of debt issuance costs		(4,595,000)	(2,195,000)
Cash and equivalents at end of period		215,694,000	287,870,000
Reportable Legal Entities [Member] | Parent Company [Member]
Proceeds from the issuance of senior notes payable		579,125,000	300,000,000
Payment of debt issuance costs		(4,595,000)	(2,195,000)
Loan from subsidiary		(12,596,000)	(41,000,000)
Net proceeds from (payments on) mortgage credit facility
(Contributions to) distributions from Corporate and subsidiaries		1,210,000	8,300,000
Repurchases of common stock		(150,014,000)	(99,829,000)
Common stock dividend payments		(9,019,000)	(9,527,000)
Issuance of common stock under employee stock plans, net of tax withholdings		(5,303,000)	1,069,000
Other financing activities
Intercompany advances, net		(71,048,000)	122,427,000
Net cash provided by (used in) financing activities		97,760,000	269,271,000
Net increase (decrease) in cash and equivalents		(64,180,000)	121,876,000
Cash and equivalents at beginning of period		105,261,000	6,387,000
Net cash provided by (used in) operating activities		(161,020,000)	(148,603,000)
Net cash provided by (used in) operating activities		(161,020,000)	(148,603,000)
Investments in unconsolidated homebuilding joint ventures		(137,000)	(178,000)
Distributions of capital from unconsolidated homebuilding joint ventures		500,000	1,107,000
Net cash paid for acquisitions
Loan to parent and subsidiaries
Other investing activities		(1,283,000)	279,000
Net cash provided by (used in) investing activities		(920,000)	1,208,000
Change in restricted cash
Borrowings from revolving credit facility		264,450,000	693,700,000
Principal payments on revolving credit facility		(264,450,000)	(693,700,000)
Principal payments on secured project debt and other notes payable			(9,974,000)
Principal payment on senior notes payable		(230,000,000)
Proceeds from Issuance of Senior Long-term Debt		579,125,000	300,000,000
Payment of debt issuance costs		(4,595,000)	(2,195,000)
Cash and equivalents at end of period		41,081,000	128,263,000
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Proceeds from the issuance of senior notes payable
Payment of debt issuance costs
Loan from subsidiary
Net proceeds from (payments on) mortgage credit facility
(Contributions to) distributions from Corporate and subsidiaries
Repurchases of common stock
Common stock dividend payments
Issuance of common stock under employee stock plans, net of tax withholdings
Other financing activities			(199,000)
Intercompany advances, net		(17,474,000)	(130,705,000)
Net cash provided by (used in) financing activities		(17,474,000)	(130,904,000)
Net increase (decrease) in cash and equivalents		(7,043,000)	(54,259,000)
Cash and equivalents at beginning of period		38,211,000	112,852,000
Net cash provided by (used in) operating activities		10,352,000	77,589,000
Net cash provided by (used in) operating activities		10,352,000	77,589,000
Investments in unconsolidated homebuilding joint ventures		(59,000)	(78,000)
Distributions of capital from unconsolidated homebuilding joint ventures		1,117,000	110,000
Net cash paid for acquisitions
Loan to parent and subsidiaries
Other investing activities		(979,000)	(976,000)
Net cash provided by (used in) investing activities		79,000	(944,000)
Change in restricted cash
Borrowings from revolving credit facility
Principal payments on revolving credit facility
Principal payments on secured project debt and other notes payable
Principal payment on senior notes payable
Proceeds from Issuance of Senior Long-term Debt
Payment of debt issuance costs
Cash and equivalents at end of period		31,168,000	58,593,000
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Proceeds from the issuance of senior notes payable
Payment of debt issuance costs
Loan from subsidiary
Net proceeds from (payments on) mortgage credit facility		(97,599,000)	(128,908,000)
(Contributions to) distributions from Corporate and subsidiaries		(1,210,000)	(8,300,000)
Repurchases of common stock
Common stock dividend payments
Issuance of common stock under employee stock plans, net of tax withholdings
Other financing activities		(67,000)
Intercompany advances, net		88,522,000	8,278,000
Net cash provided by (used in) financing activities		(14,680,000)	(123,062,000)
Net increase (decrease) in cash and equivalents		78,790,000	33,659,000
Cash and equivalents at beginning of period		64,655,000	67,355,000
Net cash provided by (used in) operating activities		151,260,000	134,628,000
Net cash provided by (used in) operating activities		151,260,000	134,628,000
Investments in unconsolidated homebuilding joint ventures		(24,806,000)	(22,336,000)
Distributions of capital from unconsolidated homebuilding joint ventures		6,428,000	6,898,000
Net cash paid for acquisitions		(44,477,000)
Loan to parent and subsidiaries		12,596,000	41,000,000
Other investing activities		(7,531,000)	(3,469,000)
Net cash provided by (used in) investing activities		(57,790,000)	22,093,000
Change in restricted cash		(3,711,000)	6,063,000
Borrowings from revolving credit facility
Principal payments on revolving credit facility
Principal payments on secured project debt and other notes payable		(615,000)	(195,000)
Principal payment on senior notes payable
Proceeds from Issuance of Senior Long-term Debt
Payment of debt issuance costs
Cash and equivalents at end of period		143,445,000	101,014,000
Consolidation, Eliminations [Member]
Proceeds from the issuance of senior notes payable
Payment of debt issuance costs
Loan from subsidiary		12,596,000	41,000,000
Net proceeds from (payments on) mortgage credit facility
(Contributions to) distributions from Corporate and subsidiaries
Repurchases of common stock
Common stock dividend payments
Issuance of common stock under employee stock plans, net of tax withholdings
Other financing activities
Intercompany advances, net
Net cash provided by (used in) financing activities		12,596,000	41,000,000
Net increase (decrease) in cash and equivalents
Cash and equivalents at beginning of period
Net cash provided by (used in) operating activities
Net cash provided by (used in) operating activities
Investments in unconsolidated homebuilding joint ventures
Distributions of capital from unconsolidated homebuilding joint ventures
Net cash paid for acquisitions
Loan to parent and subsidiaries		(12,596,000)	(41,000,000)
Other investing activities
Net cash provided by (used in) investing activities		(12,596,000)	(41,000,000)
Change in restricted cash
Borrowings from revolving credit facility
Principal payments on revolving credit facility
Principal payments on secured project debt and other notes payable
Principal payment on senior notes payable
Proceeds from Issuance of Senior Long-term Debt
Payment of debt issuance costs
Cash and equivalents at end of period