v3.19.3
ACQUIRED INTANGIBLE ASSETS - Change in Carrying Value of Intangible Assets (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Finite-lived Intangible Assets [Roll Forward]        
Acquired intangible assets, net, beginning of the period $ 84,216 $ 85,514 $ 77,102 $ 14,334
Acquisitions 0 0 14,559 75,871
Amortization expense (3,841) (4,384) (11,286) (9,075)
Transfer to assets held for sale (7,582) 0 (7,582) 0
Acquired intangible assets, net, end of the period $ 72,793 $ 81,130 $ 72,793 $ 81,130