Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset			$ 99,997		$ 0
Operating Lease, Liability, Total			93,233		$ 0
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			106,000	$ 106,000
Intangible Assets, Net (Excluding Goodwill), Total			7,300
Operating Lease, Liability, Total			$ 98,700	$ 98,700
Reclassification of Reimbursement Income From Revenues From Rental Properties for Three Months Ended Mar. 31, 2018[Member]
Prior Period Reclassification Adjustment	$ 61,200	$ 124,900
Other Rental Property for Three Months Ended Mar. 31, 2018 [Member]
Prior Period Reclassification Adjustment	$ 5,500	$ 11,100