Note 1 - Description of Business and Significant Accounting Policies - Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Trade payables	$ 12,275	$ 8,633
Revenue payables	15,535	16,665
Prepayments from partners	325	132
Miscellaneous payables	240	304
Total Accounts payable	28,375	25,734
Accrued capital expenditures	9,145	8,086
Accrued lease operating expense	980	1,100
Accrued production and other taxes	443	338
Accrued transportation and gathering	3,300	1,888
Accrued performance bonus	976	3,420
Accrued interest	402	443
Accrued office lease	1,332	598
Accrued general and administrative expense and other	901	645
Total Accrued liabilities	$ 17,479	$ 16,518