Note 15 - Fair Value Disclosure of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Marketable equity securities		$ 9,045	$ 11,936
Fair Value, Measurements, Nonrecurring [Member]
Real estate		99,693	108,313
Investments in real estate joint ventures	[1]	62,429
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Real estate
Investments in real estate joint ventures	[1]
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Real estate
Investments in real estate joint ventures	[1]
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Real estate		99,693	108,313
Investments in real estate joint ventures	[1]	62,429
Fair Value, Measurements, Recurring [Member]
Marketable equity securities		9,045	11,936
Interest rate swaps			344
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable equity securities		9,045	11,936
Interest rate swaps
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable equity securities
Interest rate swaps			344
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable equity securities
Interest rate swaps

[1] Fair value measurement as of date of deconsolidation. See Footnotes 5 and 7 to the Notes to the Consolidated Financial Statements.