Note 4 - Revenue - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue	$ 189,436	$ 142,652	$ 352,931	$ 303,829
Warrant contra revenue	(405)	(485)	(830)	(763)
Net revenue	189,031	142,167	352,101	303,066
Communications [Member]
Revenue	53,611	50,186	105,285	105,527
Health Care and Education [Member]
Revenue	40,018	9,178	57,705	22,617
E-Commerce and Consumer [Member]
Revenue	26,221	21,354	52,324	47,802
Media [Member]
Revenue	23,778	22,099	49,572	45,265
Financial and Business Service [Member]
Revenue	15,763	10,438	31,214	23,833
Travel and Hospitality [Member]
Revenue	10,542	14,179	21,039	29,965
Technology, IT and Related Service [Member]
Revenue	4,858	4,402	9,939	9,497
Other Sector [Member]
Revenue	$ 14,645	$ 10,816	$ 25,853	$ 19,323