Note 2 - Summary of Significant Accounting Policies - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued other expenses	$ 11,851	$ 7,664
Accounts payable	9,326	7,791
Bonus compensation liability	5,195	3,736
Employee liability	2,943	2,644
Refunds and commissions payable	1,533	1,805
Travel certificate liability	1,088	1,120
Royalty payable	1,005	1,010
Income tax liabilities	576	1,490
Accrued travel insurance expense	427	432
New build liability		2,730
Total accounts payable and accrued expenses	$ 33,944	$ 30,422