Note 11 - Fair Value Measurements - Estimate of Fair Value Differs From Carrying Amounts (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Mortgages [Member]
Mortgages payable, net (2)		$ 1,900
Reported Value Measurement [Member]
Notes payable, net (1)	[1]	4,520,055	$ 3,927,251
Reported Value Measurement [Member] | Mortgages [Member]
Mortgages payable, net (2)	[2]	870,125	1,139,117
Estimate of Fair Value Measurement [Member]
Notes payable, net (1)	[1]	4,476,466	3,890,797
Estimate of Fair Value Measurement [Member] | Mortgages [Member]
Mortgages payable, net (2)	[2]	$ 872,448	$ 1,141,047

[1] The Company determined that the valuation of its Senior Unsecured Notes and MTNs were classified within Level 2 of the fair value hierarchy and its Term Loan and Credit Facility were classified within Level 3 of the fair value hierarchy.

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