Note 12 - Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Note 12 - Commitments and Contingencies (Details) [Line Items]
Non-refundable Cash Deposits	$ 74,100,000
Capitalized Preacquisition and Other Development and Construction Costs	8,500,000
Remaining Purchase Price of Land Purchase and Option Contracts	$ 773,200,000
Number of Joint Ventures The Company Holds Membership Interest In	25
Number of Active Joint Ventures	13
Number of Inactive Joint Ventures	12
Number of Joint Ventures Having Project Specific Non-recourse Debt to the Company	2
Equity Method Investment Summarized Financial Information Non-recourse Debt	$ 33,704,000	$ 30,000,000
Outstanding Joint Venture Surety Bonds	0
Outstanding Surety Bonds	804,300,000
Surety Bonds Cost to Complete	465,100,000
Mortgage Loans In Process	$ 297,000,000
Mortgage Loans In Process, Interest Rate	4.10%
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 196,000,000
Mortgage Loans Committed to Sell to Investors	18,300,000
Aggregate Mortgage Loan Repurchase Payments	10,900,000
Mortgage Loans on Real Estate, New Mortgage Loans	10,100,000,000
Mortgage Loan Loss Expense Provision	300,000	500,000	$ 0
Mortgage Loan Repurchase Reserve	3,900,000	2,200,000
Mortgage Loan Repurchase Payments	$ 100,000	$ 500,000	$ 800,000
Number of Loans Repurchased	3	12	9
Operating Leases, Rent Expense	$ 6,500,000	$ 4,400,000	$ 3,800,000
Matures June, 2016 [Member]
Note 12 - Commitments and Contingencies (Details) [Line Items]
Non-recourse Joint Venture Bank Debt Scheduled for Maturity	30,000,000
Matures May 2018 [Member]
Note 12 - Commitments and Contingencies (Details) [Line Items]
Non-recourse Joint Venture Bank Debt Scheduled for Maturity	3,700,000
Closed Mortgage Loans Held for Sale [Member]
Note 12 - Commitments and Contingencies (Details) [Line Items]
Mortgage Loans Expected to Be Originated on a Non-Presold Basis	123,000,000
Mortgage Loans in Process [member]
Note 12 - Commitments and Contingencies (Details) [Line Items]
Mortgage Loans Expected to Be Originated on a Non-Presold Basis	$ 275,400,000