ACQUISITION AND RELATED PARTY ITEMS - Fair Values of Assets and Liabilties at Scil Acquisition Date (Details) - USD ($) $ in Thousands	Apr. 01, 2020	Jun. 30, 2021	Dec. 31, 2020
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Goodwill		$ 90,771	$ 88,276
Scil Animal Care Company
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination [Abstract]
Business combination, consideration transferred	$ 110,290
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash and cash equivalents	5,889
Accounts receivable	10,707
Inventories	11,278
Net investment in lease, current	311
Prepaid expenses	1,692
Other current assets	1,338
Property and equipment, net	19,320
Operating lease right-of-use assets	877
Other intangible assets, net	44,517
Net investment in leases, non-current	1,027
Investments in unconsolidated affiliates	55
Other non-current assets	291
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	97,302
Accounts payable	8,221
Accrued liabilities	7,067
Operating lease liabilities, current	356
Deferred revenue, current, and other	3,220
Deferred revenue, non-current	94
Operating lease liabilities, non-current	529
Deferred revenue, non-current	13,249
Other liabilities	276
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net, Total	64,290
Goodwill	46,000
Total fair value of consideration transferred	$ 110,290