Note 4 - Revenue - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 163,097	$ 164,630	$ 466,926	$ 487,054
Warrant contra revenue	(410)	0	(1,173)	(730)
Net Revenue	162,687	164,630	465,753	486,324
Communications [Member]
Revenue	54,834	61,439	160,362	191,684
E-Commerce and Consumer [Member]
Revenue	23,320	27,530	71,884	76,249
Financial and Business Service [Member]
Revenue	12,208	12,392	36,041	38,957
Media [Member]
Revenue	25,536	23,408	70,801	68,752
Travel and Hospitality [Member]
Revenue	15,063	18,244	45,028	52,133
Health Care and Education [Member]
Revenue	12,315	11,880	34,932	30,761
Technology, IT and Related Service [Member]
Revenue	4,813	3,063	14,310	8,958
Other Sector [Member]
Revenue	$ 15,008	$ 6,674	$ 33,568	$ 19,560