Note 2 - Property and Equipment - Summary of Property and Equipment (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Property and equipment, gross		$ 81,227,000
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization, Total	$ 79,135,000
Accumulated depreciation	(52,256,000)	(55,383,000)
Net property and equipment	26,879,000	25,844,000
Property and equipment, net	26,879,000	25,844,000
Non-US [Member]
Net property and equipment	5,984,000	3,966,000
Property and equipment, net	5,984,000	3,966,000
Medical Equipment and Facilities [Member]
Property and equipment, gross	75,272,000	77,150,000
Office Equipment [Member]
Property and equipment, gross	314,000	306,000
Construction in Progress [Member]
Property and equipment, gross	$ 3,549,000	$ 3,771,000