Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] Common Stock Class A [Member]	Common Stock [Member] Common Stock Class B [Member]	Additional Paid-In Capital [Member]	Accumulated Surplus (Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Total
Beginning balance at Dec. 31, 2018	$ 1	$ 0	$ 56,567	$ (3,387)	$ (857)		$ 52,324
Beginning balance (in shares) at Dec. 31, 2018	14,110,315	1,898,423
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	$ 0	0	14,950	0		14,950
Foreign currency translation adjustment	0	0	0	0	(2,220)		(2,220)
Exercise of stock options	$ 0	$ 0	312	0	0		312
Exercise of stock options (in shares)	193,642	0
Cancellation of stock options	$ 0	$ 0	(576)	0	0
Cancellation of stock options (In shares)	0	0
Stock-based compensation	$ 0	$ 0	2,919	0	0		2,919
Issuance of Class A common stock in connection with public offering	$ 1	$ 0	26,462	0	0		26,463
Issuance of Class A common stock in connection with public offering (in shares)	2,053,572	0
Share repurchase\cancellation	$ 0	$ 0	(2,827)	0	0		(2,827)
Share repurchase\cancellation (in shares)	(214,286)	0
Conversion of class B common stock to Class A common stock	$ 0	$ 0	0	0	0		0
Conversion of class B common stock to Class A common stock (in shares)	35,815	(35,815)
Ending balance at Sep. 30, 2019	$ 2	$ 0	82,857	11,563	(3,077)		91,345
Ending balance (in shares) at Sep. 30, 2019	16,179,058	1,862,608
Beginning balance at Jun. 30, 2019	$ 1	$ 0	58,101	2,781	(1,168)		59,715
Beginning balance (in shares) at Jun. 30, 2019	14,229,942	1,883,423
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	$ 0	0	8,782	0		8,782
Foreign currency translation adjustment	0	0	0	0	(1,909)		(1,909)
Exercise of stock options	$ 0	$ 0	140	0	0		140
Exercise of stock options (in shares)	89,015	0
Cancellation of stock options		$ 0	(576)	0	0		(576)
Cancellation of stock options (In shares)	0	0
Stock-based compensation	$ 0	$ 0	1,557	0	0		1,557
Issuance of Class A common stock in connection with public offering	$ 1	$ 0	26,462	0	0		26,463
Issuance of Class A common stock in connection with public offering (in shares)	2,053,572	0
Share repurchase\cancellation	$ 0	$ 0	(2,827)	0	0		(2,827)
Share repurchase\cancellation (in shares)	(214,286)	0
Conversion of class B common stock to Class A common stock	$ 0	$ 0	0	0	0		0
Conversion of class B common stock to Class A common stock (in shares)	20,815	(20,815)
Ending balance at Sep. 30, 2019	$ 2	$ 0	82,857	11,563	(3,077)		91,345
Ending balance (in shares) at Sep. 30, 2019	16,179,058	1,862,608
Beginning balance at Dec. 31, 2019	$ 2	$ 0	83,487	15,507	(1,675)	$ 0	97,321
Beginning balance (in shares) at Dec. 31, 2019	16,182,151	1,862,608
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	$ 0	0	10,251	0	1,585	11,836
Foreign currency translation adjustment	0	0	0	0	2,712	2,233	4,945
Exercise of stock options	$ 0	$ 0	2,191	0	0	0	2,191
Exercise of stock options (in shares)	592,946	0
Stock-based compensation	$ 0	$ 0	4,323	0	0	0	4,323
Share repurchase\cancellation	$ 0	$ 0	(9,715)	0	0	0	(9,715)
Share repurchase\cancellation (in shares)	(242,681)	0
Conversion of class B common stock to Class A common stock	$ 0	$ 0	0	0	0	0	0
Conversion of class B common stock to Class A common stock (in shares)	60,002	(60,002)
Issuance of warrants (note 12)	$ 0	$ 0	19,859	0	0	0	19,859
Exercise of stock warrant	$ 0	$ 0	0	0	0	0	0
Exercise of stock warrant (in shares)	64,717	0
Reclassification of redeemable non-controlling interest	$ 0	$ 0	0	0	0	59,958	59,958
Ending balance at Sep. 30, 2020	$ 2	$ 0	100,145	25,758	1,037	63,776	190,718
Ending balance (in shares) at Sep. 30, 2020	16,657,135	1,802,606
Beginning balance at Jun. 30, 2020	$ 2	$ 0	76,189	17,131	(3,415)	61,078	150,985
Beginning balance (in shares) at Jun. 30, 2020	16,250,092	1,802,606
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	$ 0	0	8,627	0	1,393	10,020
Foreign currency translation adjustment	0	0	0	0	4,452	1,305	5,757
Exercise of stock options	$ 0	$ 0	1,318	0	0	0	1,318
Exercise of stock options (in shares)	407,043	0
Stock-based compensation	$ 0	$ 0	2,779	0	0	0	2,779
Issuance of warrants (note 12)	0	0	19,859	0	0	0	19,859
Ending balance at Sep. 30, 2020	$ 2	$ 0	$ 100,145	$ 25,758	$ 1,037	$ 63,776	$ 190,718
Ending balance (in shares) at Sep. 30, 2020	16,657,135	1,802,606