FAIR VALUE OF FINANCIAL ASSETS AND LIABILITIES - Reconciliation of Beginning and Ending Balances (Details) - Fair Value, Measurements, Recurring - Fair Value, Inputs, Level 3 - Contingent Consideration Liability $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Contingent Liability for Accrued Consideration
Beginning balance at December 31, 2018	$ 4,319
Acquisitions and settlements
Acquisitions	0
Settlements	(1,500)
Total remeasurement adjustments:
Changes in fair value recorded in profit and loss	33
Ending Balance at March 31, 2019	2,852
The amount of total losses for the quarter included in earnings or changes to net assets, attributable to changes in unrealized losses relating to liabilities still held at March 31, 2019.	$ 33