Note 12 - Fair Value Measurements (Detail) - Estimate of Fair Value Differs from Carrying Amounts (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Marketable securities (1)	$ 76,786	[1]	$ 36,541	[1]
Marketable securities (1)	77,082	[1]	36,825	[1]
Notes payable (2)	3,337,420	[2]	3,192,127	[2]
Notes payable (2)	3,561,819	[2]	3,408,632	[2]
Mortgages payable (3)	1,113,653	[3]	1,003,190	[3]
Mortgages payable (3)	$ 1,197,711	[3]	$ 1,068,616	[3]

[1] As of March 31, 2013 and December 31, 2012, the Company determined that $73.8 million and $22.4 million, respectively, of the marketable securities estimated fair value were classified within Level 1 of the fair value hierarchy and the remaining $3.3 million and $3.4 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 liabilities was classified within Level 3 of the fair value hierarchy.