ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Accumulated other comprehensive income activity
Balance at the beginning of the period	$ 1,571,916
Other comprehensive income (loss) before reclassifications	14,940	$ (30,919)
Amounts reclassified from accumulated other comprehensive income	9,584	(10,249)
Net current-period other comprehensive income (loss)	24,524	(41,168)
Balance at the end of the period	1,759,572
Foreign Currency
Accumulated other comprehensive income activity
Balance at the beginning of the period	(257,124)	(248,401)
Other comprehensive income (loss) before reclassifications	19,282	(42,725)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income (loss)	19,282	(42,725)
Balance at the end of the period	(237,842)	(291,126)
Defined Benefit Pension Plans
Accumulated other comprehensive income activity
Balance at the beginning of the period	(83,147)	(60,463)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	4,639	2,150
Net current-period other comprehensive income (loss)	4,639	2,150
Balance at the end of the period	(78,508)	(58,313)
Derivatives
Accumulated other comprehensive income activity
Balance at the beginning of the period	(1,677)	(1,640)
Other comprehensive income (loss) before reclassifications	(4,342)	11,806
Amounts reclassified from accumulated other comprehensive income	4,945	(12,399)
Net current-period other comprehensive income (loss)	603	(593)
Balance at the end of the period	(1,074)	(2,233)
Accumulated Other Comprehensive Income/(Loss)
Accumulated other comprehensive income activity
Balance at the beginning of the period	(341,948)	(310,504)
Balance at the end of the period	$ (317,424)	$ (351,672)