Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset		$ 104,177,000
Operating Lease, Liability, Total		97,133,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset		106,000,000	$ 106,000,000
Intangible Assets, Net (Excluding Goodwill), Total		7,300,000
Operating Lease, Liability, Total		$ 98,700,000	$ 98.70
Reclassification of Reimbursement Income From Revenues From Rental Properties for Three Months Ended Mar. 31, 2018[Member]
Prior Period Reclassification Adjustment	$ 63,700,000
Other Rental Property for Three Months Ended Mar. 31, 2018 [Member]
Prior Period Reclassification Adjustment	$ 5,600,000