ACCUMULATED OTHER COMPREHENSIVE LOSS (Changes in Accumulated Other Comprehensive Loss by Component) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Components of Other Accumulated Income, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,084,241
Other comprehensive income before reclassifications	44,844
Amounts reclassified out of accumulated other comprehensive loss	222
Tax effects	(208)
Other comprehensive income	44,858
Balance at end of period	1,128,347
Foreign Currency Translation
Components of Other Accumulated Income, Net of Tax [Roll Forward]
Balance at beginning of period	(212,211)
Other comprehensive income before reclassifications	44,545
Amounts reclassified out of accumulated other comprehensive loss	0
Tax effects	0
Other comprehensive income	44,545
Balance at end of period	(167,666)
Unrealized (Losses) Gains on Available-For-Sale Securities
Components of Other Accumulated Income, Net of Tax [Roll Forward]
Balance at beginning of period	(321)
Other comprehensive income before reclassifications	299
Amounts reclassified out of accumulated other comprehensive loss	222
Tax effects	(208)
Other comprehensive income	313
Balance at end of period	(8)
Unfunded Pension Liability
Components of Other Accumulated Income, Net of Tax [Roll Forward]
Balance at beginning of period	(1,794)
Other comprehensive income before reclassifications	0
Amounts reclassified out of accumulated other comprehensive loss	0
Tax effects	0
Other comprehensive income	0
Balance at end of period	(1,794)
Total
Components of Other Accumulated Income, Net of Tax [Roll Forward]
Balance at beginning of period	(214,326)
Balance at end of period	$ (169,468)