Note 3 - Property and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equipment [Member]
Capital Leases, Balance Sheet, Assets by Major Class, Net	$ 51,000	$ 1,200,000
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation	6,000,000	4,800,000
Capital Leases, Income Statement, Amortization Expense	1,200,000	1,600,000	$ 1,700,000
Depreciation	$ 30,328,000	$ 32,864,000	$ 31,360,000