Note 15 - Fair Value Disclosure of Financial Instruments - Estimate of Fair Value Differs From Carrying Amounts (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Mortgages [Member]
Mortgages and construction loan payable, net (2)		$ 13,100	$ 19,300
Reported Value Measurement [Member]
Notes payable, net (1)	[1]	4,381,456	4,596,140
Reported Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	492,416	882,787
Estimate of Fair Value Measurement [Member]
Notes payable, net (1)	[1]	4,126,450	4,601,479
Estimate of Fair Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	$ 486,341	$ 881,427

[1] The Company determined that the valuation of its Senior Unsecured Notes were classified within Level 2 of the fair value hierarchy and Credit Facility were classified within Level 3 of the fair value hierarchy. The estimated fair value amounts classified as Level 2 as of December 31, 2018 and 2017, were $4.0 billion and $4.6 billion, respectively. The estimated fair value amounts classified as Level 3 as of December 31, 2018 and 2017, were $97.6 million and $1.9 million, respectively.

[2] The Company determined that its valuation of these Mortgages payable was classified within Level 3 of the fair value hierarchy.