ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Accumulated other comprehensive income activity
Balance at the beginning of the period	$ 1,173,950
Balance at the end of the period	1,321,514
Foreign Currency
Accumulated other comprehensive income activity
Balance at the beginning of the period	(259,888)	$ (206,725)
Other comprehensive income (loss) before reclassifications	69,493	44,329
Amounts reclassified from accumulated other comprehensive income		(82)
Net current-period other comprehensive income (loss)	69,493	44,247
Balance at the end of the period	(190,395)	(162,478)
Defined Benefit Pension Plans
Accumulated other comprehensive income activity
Balance at the beginning of the period	(59,775)	(55,550)
Amounts reclassified from accumulated other comprehensive income	2,699	2,511
Net current-period other comprehensive income (loss)	2,699	2,511
Balance at the end of the period	(57,076)	(53,039)
Other
Accumulated other comprehensive income activity
Balance at the beginning of the period	(46)	(72)
Other comprehensive income (loss) before reclassifications	(9,237)
Amounts reclassified from accumulated other comprehensive income	5,667	19
Net current-period other comprehensive income (loss)	(3,570)	19
Balance at the end of the period	(3,616)	(53)
Accumulated Other Comprehensive Income/(Loss)
Accumulated other comprehensive income activity
Balance at the beginning of the period	(319,709)	(262,347)
Other comprehensive income (loss) before reclassifications	60,256	44,329
Amounts reclassified from accumulated other comprehensive income	8,366	2,448
Net current-period other comprehensive income (loss)	68,622	46,777
Balance at the end of the period	$ (251,087)	$ (215,570)