ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Accumulated other comprehensive income activity
Balance at the beginning of the period	$ 1,571,916
Balance at the end of the period	1,645,631
Foreign Currency
Accumulated other comprehensive income activity
Balance at the beginning of the period	(257,124)	$ (248,401)
Other comprehensive income (loss) before reclassifications	(23,134)	(197)
Net current-period other comprehensive income (loss)	(23,134)	(197)
Balance at the end of the period	(280,258)	(248,598)
Defined Benefit Pension Plans
Accumulated other comprehensive income activity
Balance at the beginning of the period	(83,147)	(60,463)
Amounts reclassified from accumulated other comprehensive income	3,076	1,437
Net current-period other comprehensive income (loss)	3,076	1,437
Balance at the end of the period	(80,071)	(59,026)
Derivatives
Accumulated other comprehensive income activity
Balance at the beginning of the period	(1,677)	(1,640)
Other comprehensive income (loss) before reclassifications	1,758	3,727
Amounts reclassified from accumulated other comprehensive income	(1,008)	(4,599)
Net current-period other comprehensive income (loss)	750	(872)
Balance at the end of the period	(927)	(2,512)
Accumulated Other Comprehensive Income/(Loss)
Accumulated other comprehensive income activity
Balance at the beginning of the period	(341,948)	(310,504)
Other comprehensive income (loss) before reclassifications	(21,376)	3,530
Amounts reclassified from accumulated other comprehensive income	2,068	(3,162)
Net current-period other comprehensive income (loss)	(19,308)	368
Balance at the end of the period	$ (361,256)	$ (310,136)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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