DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue recognition	$ 57,252	$ 52,979	$ 48,470	$ 49,774	$ 47,966	$ 51,337	$ 54,357	$ 52,887	$ 208,475	$ 206,547	$ 201,576
Sales of generic pharmaceutical products [Member]
Revenue recognition									147,257	128,729	117,451
Sales of branded pharmaceutical products [Member]
Revenue recognition									47,960	63,767	60,554
Sales of contract manufactured products [Member]
Revenue recognition									9,221	11,139	9,119
Royalties from licensing agreements [Member]
Revenue recognition									1,396	807	12,504
Product development services [Member]
Revenue recognition									1,858	1,125	1,019
Other [Member]
Revenue recognition									$ 783	$ 980	$ 929