Note 11 - Fair Value Measurements - Estimate of Fair Value Differs From Carrying Amounts (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Reported Value Measurement [Member]
Notes payable, net (1)	[1]	$ 4,961,972	$ 4,831,759
Reported Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	388,406	484,008
Estimate of Fair Value Measurement [Member]
Notes payable, net (1)	[1]	5,044,336	4,983,763
Estimate of Fair Value Measurement [Member] | Mortgages [Member]
Mortgages and construction loan payable, net (2)	[2]	$ 387,440	$ 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 and term loan were classified within Level 3 of the fair value hierarchy. The estimated fair value amounts classified as Level 2, as of June 30, 2020 and December 31, 2019, were $4.7 billion and $4.8 billion, respectively. The estimated fair value amounts classified as Level 3, as of June 30, 2020 and December 31, 2019, were $325.0 million and $199.9 million, respectively.

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