Note 11 - Fair Value Measurements - Estimate of Fair Value Differs From Carrying Amounts (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Reported Value Measurement [Member]
Notes payable, net (1)	[1]	$ 5,042,737	$ 4,831,759
Reported Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	314,641	484,008
Estimate of Fair Value Measurement [Member]
Notes payable, net (1)	[1]	5,298,739	4,983,763
Estimate of Fair Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	$ 315,301	$ 486,042

[1] The Company determined that the valuation of its Senior Unsecured Notes were classified within Level 2 of the fair value hierarchy and its unsecured revolving credit facility was classified within Level 3 of the fair value hierarchy. The estimated fair value amounts classified as Level 2, as of September 30, 2020 and December 31, 2019, were $5.3 billion and $4.8 billion, respectively. The estimated fair value amounts classified as Level 3, as of December 31, 2019, was $199.9 million.

[2] The Company determined that its valuation of its mortgages and construction loan were classified within Level 3 of the fair value hierarchy.