Note 11 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Measurements, Nonrecurring [Member]
Real estate	$ 40,558	$ 117,930
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Real estate
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Real estate
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Real estate	40,558	117,930
Fair Value, Measurements, Recurring [Member]
Marketable equity securities	12,715	6,502
Interest rate swaps	667	975
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable equity securities	12,715	6,502
Interest rate swaps
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable equity securities
Interest rate swaps	667	975
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable equity securities
Interest rate swaps