Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	$ 871,334	$ 857,144
Weighted Average Maturity	3 years 292 days
Weighted Average Interest Rate	3.69%
Percentage of Total	100.00%
Fixed Rate Debt [Member] | Floating Rate Debt (Hedged) [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	326,702
Weighted Average Maturity	3 years 328 days
Weighted Average Interest Rate	3.28%
Percentage of Total	37.00%
Fixed Rate Debt [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	271,242
Weighted Average Maturity	4 years 73 days
Weighted Average Interest Rate	5.76%
Percentage of Total	31.00%
Fixed Rate Debt, Considering Hedges [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	597,944
Weighted Average Maturity	4 years
Weighted Average Interest Rate	4.40%
Percentage of Total	68.00%
Variable Rate Debt [Member] | Floating Rate Debt (Hedged) [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	(326,702)
Weighted Average Maturity	minus 3 years 328 days
Weighted Average Interest Rate	(2.14%)
Percentage of Total	(37.00%)
Variable Rate Debt [Member] | Construction Loans [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	164,158	144,389
Weighted Average Maturity	1 year 109 days
Weighted Average Interest Rate	2.33%
Percentage of Total	19.00%
Variable Rate Debt [Member] | Notes Payable, Other Payables [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	60,871
Weighted Average Maturity	4 years 146 days
Weighted Average Interest Rate	2.38%
Percentage of Total	7.00%
Variable Rate Debt [Member] | Corporate Debt Securities [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	375,000
Weighted Average Maturity	4 years 6 months
Weighted Average Interest Rate	2.01%
Percentage of Total	43.00%
Variable Rate Debt, Considering Hedges [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	273,327
Weighted Average Maturity	3 years 109 days
Weighted Average Interest Rate	2.14%
Percentage of Total	32.00%
Net Premiums On Acquired Debt [Member]
Note 4 - Mortgage and Other Indebtedness (Details) - Consolidated Indebtedness by Type of Interest Rate [Line Items]
Amount (in Dollars)	$ 63	$ 66
Weighted Average Maturity
Weighted Average Interest Rate
Percentage of Total