Note 23 - Quarterly Financial Information (Unaudited) - Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer, Excluding Assessed Tax, Total	$ 20,177	[1]	$ 65,684	$ 70,864	$ 48,501	$ 65,513	$ 81,422	$ 88,336	$ 55,747	[1]	$ 205,226	$ 291,018	$ 275,026
Gross profit	62,145	[1]	5,462	3,270	3,262	14,967	12,653	8,271	37,507	[1]	74,139	73,398	20,261
Net income	$ 72,373		$ 6,622	$ 3,687	$ 5,499	$ 1,836	$ 9,445	$ 6,051	$ 35,826		$ 88,181	$ 53,158	$ 23,511
Basic (in dollars per share)	$ 1.65		$ 0.15	$ 0.08	$ 0.13	$ 0.04	$ 0.22	$ 0.14	$ 0.82		$ 2.02	$ 1.22	$ 0.54
Diluted (in dollars per share)	$ 1.65		$ 0.15	$ 0.08	$ 0.13	$ 0.04	$ 0.22	$ 0.14	$ 0.82		$ 2.02	$ 1.22	$ 0.54

[1] The fourth quarter of 2019 and the first quarter of 2018 includes the retroactive reinstatement of the BTC in revenue and gross profit (see Note 3 for further information).