Note 15 - Fair Value Disclosure of Financial Instruments - Estimate of Fair Value Differs From Carrying Amounts (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Mortgages [Member]
Mortgages and construction loan payable, net (2)		$ 7,900	$ 13,100
Reported Value Measurement [Member]
Notes payable, net (1)	[1]	4,831,759	4,381,456
Reported Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	484,008	492,416
Estimate of Fair Value Measurement [Member]
Notes payable, net (1)	[1]	4,983,763	4,126,450
Estimate of Fair Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	$ 486,042	$ 486,341

[1] The Company determined that the valuation of its Senior Unsecured Notes were classified within Level 2 of the fair value hierarchy and its Credit Facility was classified within Level 3 of the fair value hierarchy. The estimated fair value amounts classified as Level 2 as of December 31, 2019 and 2018, were $4.8 billion and $4.0 billion, respectively. The estimated fair value amounts classified as Level 3 as of December 31, 2019 and 2018, were $199.9 million and $97.6 million, respectively.

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