Note 7 - Summary of Interest Expense on Revolving Credit Facility and Commitment Fees and Unused Revolving Credit Facility (Details) - Revolving Credit Facility [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest expense	$ 4,117	$ 4,186	$ 8,156
Commitment fees	$ 1,513	$ 1,465	$ 887