ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications From Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Amount Reclassified from Accumulated Other Comprehensive Income
Interest expense	$ (7,415)	$ (8,388)
Miscellaneous, net	(963)	(1,412)
Income before Income Taxes	100,888	78,036
Tax benefit	(16,949)	(22,786)
Net Income Attributable to AptarGroup, Inc.	83,952	55,253
Amount Reclassified from Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Net Income Attributable to AptarGroup, Inc.	(2,154)	(1,907)
Defined Benefit Pension Plans | Amount Reclassified from Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Amortization of net loss	3,092	2,062
Amortization of prior service cost	45	97
Income before Income Taxes	3,137	2,159
Tax benefit	(750)	(523)
Net Income Attributable to AptarGroup, Inc.	2,387	1,636
Derivatives | Amount Reclassified from Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Net Income Attributable to AptarGroup, Inc.	(4,541)	(3,543)
Derivatives | Changes in cross currency swap: interest component | Amount Reclassified from Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Interest expense	(12)	(763)
Derivatives | Changes in cross currency swap: foreign exchange component | Amount Reclassified from Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Miscellaneous, net	$ (4,529)	$ (2,780)