Note 11 - Fair Value Measurements (Details) - Financial Instruments: Estimate of Fair Value Differs from Carrying Amounts (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Financial Instruments: Estimate of Fair Value Differs from Carrying Amounts [Abstract]
Marketable securities (1)	$ 105,253	[1]	$ 90,235	[1]
Marketable securities (1)	105,108	[1]	90,035	[1]
Notes payable (2)	3,679,237	[2]	3,171,742	[2]
Notes payable (2)	3,836,369	[2]	3,313,936	[2]
Mortgages payable (3)	2,042,014	[3]	1,424,228	[3]
Mortgages payable (3)	$ 2,103,356	[3]	$ 1,481,138	[3]

[1] As of March 31, 2015 and December 31, 2014, the Company determined that $102.7 million and $87.7 million, respectively, of the Marketable securities estimated fair value were classified within Level 1 of the fair value hierarchy and the remaining $2.4 million and $2.3 million, respectively, were classified within Level 3 of the fair value hierarchy.

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

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