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BUSINESS COMBINATIONS - Preliminary purchase price (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 01, 2019	May 01, 2019
Assets acquired and liabilities assumed:
Intangible assets			$ 2,595
Total	$ 751
Smithers Avanza Toxicology Services LLC acquisition
Assets acquired and liabilities assumed:
Receivables	1,128
Property and equipment	1,564
Prepaid expenses	147
Goodwill	545
Accrued expenses	(219)
Customer advances	(570)
Total	2,595
PCRS acquisition
Assets acquired and liabilities assumed:
Receivables	578
Property and equipment	2,836
Unbilled receivables	162
Prepaid expenses	27
Intangible assets	2,081	$ 5,857
Goodwill	751
Accounts payable	(109)
Accrued expenses	(118)
Customer advances	(351)
Total	$ 5,857