ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Components of accumulated other comprehensive loss:
Balance at the beginning of the period	$ 3,034	$ 32,387
Other comprehensive (loss) income before reclassifications	(46,529)	(142)
Amounts reclassified from accumulated other comprehensive (loss) income	0
Net current-period other comprehensive (loss) income	(46,529)	(142)
Balance at the end of the period	(43,495)	32,529
Currency Translation Gains (Losses)
Components of accumulated other comprehensive loss:
Balance at the beginning of the period	2,950	(32,581)
Other comprehensive (loss) income before reclassifications	(46,412)	(338)
Amounts reclassified from accumulated other comprehensive (loss) income	0
Net current-period other comprehensive (loss) income	(46,412)	(338)
Balance at the end of the period	(43,462)	(32,919)
Unrealized Gains (Losses) on Available-for-Sale Securities
Components of accumulated other comprehensive loss:
Balance at the beginning of the period	84	194
Other comprehensive (loss) income before reclassifications	(117)	196
Amounts reclassified from accumulated other comprehensive (loss) income	0
Net current-period other comprehensive (loss) income	(117)	196
Balance at the end of the period	$ (33)	$ 390